The Julio Claudian | Roman Architecture | Second edition

The Julio Claudian | Roman Architecture | Second edition

The Julio-Claudians | Roman Architecture | Second edition | (Part-01)

The Julio Claudian | Roman Architecture | Second edition

In ad 4 Augustus adopted Tiberius, the son of his wife Livia by a previous marriage, after all his other heirs had died. Tiberius was descended on both sides from the aristocratic Claudian family, which boasted 28 consulships, five dictatorships, seven censorships, six triumphs, and two ovations (Suet., Tib. 1.2). His own career too was one of unbroken success. He was awarded a triumph for his campaign in Germany. His private life, however, was less happy. In 11 bc he was forced by Augustus to divorce his wife, Vipsania, whom he adored, to marry Augustus’ daughter, Julia, for whom he came to feel such a passionate loathing that at the height of his career in 6 bc he retired to Rhodes for more than seven years. Julia’s scandalous conduct eventually resulted in her banishment in 2 bc and in ad 2 Tiberius returned to Rome, taking up residence soon afterwards in the Gardens of Maecenas (Suet., Tib. 15).

The architectural climate in Rome changed abruptly after the death of Augustus in ad 14. Tiberius (ad 14–37) did not have the same passion for building marble temples. In fact he did not build any magnificent works apart from the Temple of Augustus and the reconstruction of the Theatre of Pompey, both of which remained unfinished for many years (Suet., Tib. 47). The theatre had been damaged in the fire of ad 22 and the restoration was begun by Tiberius on the grounds that no member of Pompey’s family was equal to the task of restoration (Tacitus, Ann. 3.72). Although it was customary under these circumstances for the building to be named after its restorer, he decreed that the name of Pompey was to remain. He also erected a bronze statue of the praetorian prefect, Sejanus, in the theatre (Dio, 57.21.3), and rebuilt the scene building (Tacitus, Ann. 6.45.2), but the restoration was not completed until the time of Caligula (Suet., Cal. 21). The construction of the Temple of Augustus was entrusted to Tiberius and his mother Livia in a senatorial decree of ad 14 and Tiberius was about to inaugurate it in ad 37, when death intervened. The temple has never been found, although its location is known with a fair degree of accuracy and it is frequently mentioned in the literature (Dio, 57.10.2). It is behind the Basilica Julia in an area which has never been excavated. It was later used as one of the supports for Caligula’s infamous bridge which he used to cross from the Imperial palace on the Palatine to the Temple of Jupiter on the Capitol. Caligulan coins show the temple as a hexastyle building in the Ionic style. It was rebuilt by Domitian and again by Antoninus Pius, whose coins show it as an octastyle building. Nothing is heard of it after that.

Another legacy of Augustus was the imperial residence on the Palatine, the Domus Augusti, an agglomeration of modest houses rather than a palace. Immediately to the north of it is the enormous platform (400 × 450 Roman feet [118.4 × 133.2 metres]) where the Domus Tiberiana stood. Our present knowledge of this complex, most of which is buried beneath the Farnese gardens, suggests that at the time of Tiberius the Domus Tiberiana was nothing more than a few older houses, perhaps including the house in which Tiberius was born. It was Nero who built the terraced platform and palatial complex, which from ad 69 was known as the Domus Tiberiana (Tacitus, Hist. 1.27; Plutarch, Galba 24.7). In ad 16 an arch was erected in the Forum near the Temple of Saturn in honour of Tiberius and his adopted son Germanicus. It was to commemorate the recovery of the standards lost by Varus to the Germans in ad 9 (Tacitus, Ann. 2.41). It had only one opening, as shown by the excavations of 1900 and the representation of it on a frieze of the Arch of Constantine. It is shown plain and unadorned, but so too is the Arch of Septimius Severus. It may have followed the pattern of Augustus’ arches in the Forum with victories in the spandrels and statuary on the attic, but otherwise without ornament.1 In ad 19 after Artaxias had been made king of Armenia the senate voted ovations for Germanicus and Tiberius’ son, Drusus the Younger, and erected arches to them each side of the Temple of Mars Ultor (Figure 3.11) (Tacitus, Ann. 2.64). Yet another arch was erected to Germanicus, who died later in the same year (Tacitus, Ann. 2.83), although Tacitus could be referring to the same arch. After the death of Drusus in ad 23 the senate decreed that he should be honoured as Germanicus had, perhaps meaning that yet another arch was erected (Tacitus, Ann. 4.9).

Between ad 20–23 on high ground NE of the city centre, and away from its temptations (Tacitus, Ann. 4.2), Tiberius built an enormous camp for the Praetorian guard, a body which in future was to have a preponderant influence on the imperial succession. He did so on the advice of the praetorian prefect Sejanus (Dio, 57.19.6), who was steadily increasing his influence over the emperor. Commanding a good view of the roads leading into Rome from the north and east, it had the usual rectangular shape (440 × 380 metres) with curved corners and a gate on each of the four sides. It was defended by a wall of opus testaceum, 4.73 metres high, with merlons every 3 metres. Behind it was a continuous series of barrel-vaulted rooms in opus reticulatum, 3 metres high × c. 3.60 metres wide, above which was the wall-walk. Parts of the barrack buildings and granaries came to light in the period 1960–1968 before the National library was built. Most of the outer circuit of the Castra Praetoria was eventually incorporated into the Aurelianic walls. Although the north and east gates were walled up and the outer wall itself was raised about 5 metres by Aurelian, and a further 2.5 metres at the time of Maxentius, most of the Tiberian work is still visible.

By ad 26 Tiberius seems to have lost interest in Rome, which he left, never to return. One day he was dining in a villa called spelunca (cave) in a locality in Campania now known as Sperlonga, clearly a corruption of the Latin word, when part of the roof collapsed almost killing him (Suet., Tib. 39). Sejanus, who was travelling with him, saved the emperor’s life, thus greatly increasing his power and influence (Tacitus, Ann. 4.59). Excavated in 1957 the villa’s focal point is a large natural cavern in the rocky cliffs which meet the sea at this point of the coast (Figure 5.1). Concrete walling and masonry flooring were added to the natural cave with, on the left on entering, a minor grotto with a spur of rock carved into the shape of a ship’s prow, inscribed in mosaic Navis Argo. Immediately to the south of this is a large rectangular basin in the middle of which is a rectangular structure on which was perhaps built a cenatio (dining area) and a vivarium (fish-pond). Linked to it is a circular basin with a statue group of Scylla attacking the helmsman of one of Odysseus’ ships on a small island in the middle. To the NE of the circular basin concrete walling created a circular room, probably the triclinium where Sejanus saved the emperor’s life, with a small bedroom behind. To the SE of the circular basin is a deep hollow which provided a theatrical setting for a magnificent sculptural group in white marble showing the Cyclops being blinded by Odysseus and his followers, now in the museum. Five seats were cut in the rock each side of the main cave to allow spectators to observe the spectacle. The sculptures, carved in a dramatic Hellenistic style, are signed by Rhodian sculptors, which suggests a connection with

Figure 5.1  Sperlonga, Grotto of Tiberius, early first century ad: plan

the emperor’s stay on that island, although some scholars date them to the Flavian period. The grotto at Sperlonga exemplifies the Roman delight in uniting architecture, landscape and sculpture into a single entity.

Tiberius spent several years in the seclusion of Capreae (Capri), and it was through a letter that he finally ordered the arrest and execution of Sejanus, who fell from power in ad 31. His self-imposed exile to Capri led to ugly rumours about his debauched life there, although Augustus, who had taken over the island as an imperial estate (Suet., Aug. 92), was never criticised for living in the country. Tiberius added several more buildings, embellished a number of natural grottoes and built the Villa Jovis, perched on the edge of a sheer cliff on the eastern tip of the island (Figure 5.2). The cliff falls away to the north, east and south, and a level site was created by cutting back the rock to build a huge undercrofting of concrete barrel-vaults. Part of this vast network was used as an immense water cistern to collect and store the infrequent but heavy rainfall. The cistern was vaulted over to form a flat square platform in the centre of the villa (Figure 5.3). The platform was probably covered with mosaics and perhaps surrounded on four sides by a peristyle of columns like the square of the cisterns at Ptolemais. The villa must have presented an extremely imposing aspect to visitors, who would have approached it, not by the modern pathway from the south, but from the NW up the steeper Roman road paved with bricks laid in a herringbone pattern. The villa would have towered above them, its main rooms standing more than 20 metres above the rising ground. In the SW corner is the entrance vestibule, with four green cipollino marble columns supporting the ceiling and a niche in which stood a statue, perhaps of the Emperor. From there a mosaic-paved ramp led up eastwards past a bathing suite on the south side of the complex. On the east side was a huge semicircular audience hall flanked by lesser halls. Only the

Figure 5.2  Capri, Villa Jovis: section and plan. (After A. Boethius and J. B. Ward Perkins, Etruscan and Roman Architecture [Harmondsworth: Penguin, 1970]). .

Figure 5.3  Capri, Villa Jovis, ad 14–17

substructures now survive, but they must have required an immense work of cutting, levelling and buttressing. The rooms commanded stupendous views of Sorrento and Vesuvius, situated as they are on the edge of a 300-metre-high cliff. On the north side is the emperor’s private suite, approached by a single, well-guarded corridor and kept quite separate from the service rooms and kitchens on the west side of the villa. A long corridor leads northwards to a loggia (ambulatio), 100 metres long, running close to the edge of the cliff. Here the emperor would have strolled after eating and resting in the rooms that opened off it to the south. The triclinium, with its splendid views, was a vaulted room with polychrome marble paving on its floor. In his last years Tiberius was haunted by the spectre of impending death and it was his habit to consult soothsayers. West of the main block of the villa are the massive foundations of the observatory used by his adviser and astrologer, Thrasyllus. At the edge of the cliff to the south of the villa are the remains of a lighthouse which was used mainly for signalling to the mainland opposite. The emperor’s orders could also be transmitted to a signalling tower at Cape Misenum where the imperial fleet stood ready for the emperor’s command. The lighthouse collapsed a few days before Tiberius’ death in ad 37 (Suet., Tib. 74).

After the death of Tiberius, Caligula, son of the popular Germanicus, was proclaimed emperor by the Praetorian guard, and began his reign amidst general enthusiasm, but his cruel excesses resulted in his being murdered by his own guards after only four years. During that period he did make some notable architectural contributions, by dedicating the Temple of Deified Augustus and completing the restoration of the Theatre of Pompey which had been left unfinished by Tiberius (Suet., Cal. 21). It was not, however, dedicated until the time of Claudius (Suet., Claud. 21). He probably built the large temenos dedicated to Isis and Serapis just east of the Saepta, because Augustus had banned the worship of Egyptian deities within the pomerium (Dio, 53.2.4). He despised the amphitheatre of Statilius Taurus, and so began building a wooden amphitheatre near the Saepta, which involved the destruction of many large buildings (Dio, 59.10.5). Two engineering marvels, the Anio Novus and the Aqua Claudia, were both begun by Caligula in ad 38. These were finally completed by Claudius, but the amphitheatre project was abandoned (Suet., Cal. 21). Caligula constructed a Circus in the Vatican, parts of which are said to have been found under St. Peter’s (Suet., Claud. 21). The 25.5-metre-high obelisk from Heliopolis which now stands in the middle of St. Peter’s Square is thought to have stood on the spina. It was brought to Rome by a ship of huge dimensions (Suet., Claud. 20). The ship was later sunk in the harbour at Ostia to provide a foundation for the lighthouse of Claudius.

It is said that Caligula extended the Domus Tiberiana to the Forum and converted the Temple of Castor and Pollux into a vestibule (Suet., Cal. 22). Suetonius goes on to say that he would often stand between the two statues to be worshipped by those who came there. Boni’s excavations of 1900–1901 in the angle between the Vicus Tuscus and the Temple of Castor and Pollux revealed a complex comprising an atrium, measuring 27 × 22.5 metres, and an adjoining piscina set in an open area measuring 41 × 23 metres. Immediately to the SE of the piscina was a ramp leading up from Forum level to the Palatine. It has been suggested that the entrance to this complex was through the Temple of Castor and Pollux via a bridge over the gap between the two buildings.2 This implies that the principal rooms of the Domus Gai were on the first floor at about the level of the temple podium.

In 1928 the level of Lake Nemi was lowered to reveal two enormous pleasure galleys buried in the mud. They were presumably like the ones described by Suetonius (Cal. 38):

He also constructed ten-oared Liburnian galleys with sterns studded with gems, multicoloured sails, and ample space for baths, porticoes, and dining rooms, and with a great variety of vines and fruit-bearing trees; reclining on these ships all day long he would sail along the Campanian coast amid choral dancing and singing.

The ships found at Nemi no longer exist because they were destroyed in 1944, but they were well documented and much of their furnishing survives. They were very broad in the beam, 20 metres and 24 metres respectively, and were 72 and 73.5 metres long. They were 1,100 tonnes in burden, ten times as much as Christopher Columbus’ largest ship. Flat tiles set in mortar were found in the hulls, which were laid over the oak decking. The pavements were of polychrome marble and mosaic. Flanged tiles were found which suggests that there were heated floors and perhaps baths on board these sumptuous vessels. The galleys contained a number of technical devices such as pump-pistons, pulleys and anchors. We hear of Ptolemy IV building an exotic pleasure galley equipped with similarly lavish equipment in 200 BC (Athenaeus, Deipn. 204E-208), which suggests that the inspiration for this type of pleasure galley was probably Hellenistic.

When Caligula was murdered by the Praetorian guard his uncle, Claudius, was proclaimed emperor. Claudius (ad 41–54) had a strong practical streak and his reign was mostly notable, as far as building was concerned, for engineering projects like draining of the Fucine Lake, repairing the emissary of Lake Albano, completing the two aqueducts begun by Caligula and building the harbour at Ostia. Claudius finally rededicated Pompey’s theatre which had been damaged by fire in ad 22 (Tacitus, Ann. 3.72). He ‘opened the games at the dedication of Pompey’s theatre … from a raised seat in the orchestra, after first offering sacrifice at the temples in the upper part of the cavea and coming down through the tiers of seats while all sat in silence’ (Suet., Claud. 21.1). In ad 51–52 a single arch flanked by engaged Corinthian columns was built over the Via Lata to commemorate his bringing under Roman control ‘barbarian people across the Ocean’, an allusion to his conquest of Britain. It may be that Agrippa’s crossing of the Aqua Virgo over the Via Lata was turned into this commemorative arch (CIL 6.920, 31203).

One of the aqueducts begun by Caligula was the Anio Novus, and the other is now known as the Aqua Claudia. Running at a steady incline above and below ground, through mountains, and across valleys, the two aqueducts were considered by Pliny to be the most remarkable in the world (Nat.Hist. 36.24.122–3). The Aqua Claudia, finished by Claudius in ad 52, is perhaps the most impressive of Roman aqueducts. Its arches, which begin near the seventh mile of the Via Latina, are still a remarkable sight as they approach Rome, and must have been particularly spectacular at the two points where they intersected and crossed the arches of the Aqua Marcia. The Anio Novus was carried on the same arches in a channel (specus) immediately above.

The Claudia was carried over the Via Praenestina by a double archway, built of heavily rusticated travertine masonry, later incorporated into the Aurelianic walls and now known as the Porta Maggiore (Figure 5.4). The twin openings are flanked by three aedicules each with a pair of Corinthian half-columns supporting a tall triangular pediment. The attic carries three inscriptions put up successively by Claudius, Vespasian and Titus. The masonry of the lower part of the arch was deliberately left rough and the columns supporting the aedicules are actually composed of a number of battered or unfinished Corinthian capitals laid one on top of the other. This curious mannerism may well have been a fancy of the emperor because other examples of rusticated work exist from this period. The arch which carried the aqueducts over the Via Labicana is known from by a Rossini drawing of 1829 to have also had rusticated masonry. The emissary which regulated the level of Lake Albano, originally constructed in the fourth century bc, was repaired at about this time, possibly by Claudius. The

Figure 5.4  Rome, Porta Praenestina, now known as Porta Maggiore, built by Claudius (ad 41–54) to carry the Aqua Claudia and the Anio Novus over the Via Praenestina and the Via Labicana, and later incorporated into the Aurelianic walls.

masonry around the mouth of the emissary has rusticated and irregularly projecting voussoirs like those on the two Claudian aqueduct arches. The Porticus of Claudius at Ostia and the early first century ad amphitheatre at Verona have similar rustication. However, there are earlier examples of such rustication, for example the Roman theatre at Iguvium (Gubbio) dating to 40–30 bc3. A final work which has stylistic similarities with these other Claudian monuments is the Temple of Deified Claudius on the Caelian Hill, which had been begun by Claudius’ wife, Agrippina, but left unfinished until the time of Vespasian (Suet., Vesp. 9). Part of the platform may still be seen in the gardens of the Passionist Fathers just opposite the church of Sts. John and Paul. This interesting survival is important because it employs a similar type of rusticated blocks, heavily rusticated arches, sharply projecting keystones and flat pilasters only partly carved out of rough unfinished masonry (Figure 5.5).

Claudius died in ad 54, probably of poison (Suet., Claud. 44), and was succeeded by his adopted son, Nero. At the beginning of his reign he deified his predecessor, Claudius, while his mother, Agrippina, started his temple. Once he had murdered his mother in ad 59 Nero pulled down the Temple of Claudius, apart from its substructures part of which he used for the Domus Aurea. Although wits mocked his singing, acting and chariot-racing, Nero left a great legacy in terms of art and architecture. Because many important artistic developments took place during his reign much is owed to this versatile emperor’s patronage. Sculptors in marble and bronze, mosaicists, painters, engineers and architects and other artists of ability and renown worked for his court, and many of their achievements are still to be seen. It can be argued that the discovery of his Golden House (the Domus Aurea) at the end of the 15th century was the greatest single stimulus for artists of the Italian Renaissance. His reign is

Figure 5.5  Rome, Temple of Deified Claudius, completed by Vespasian after ad 70: temple terrace

regarded as a turning point in the exploitation of concrete as a building material. His court painter, Famulus or Fabullus, worked on the Domus Aurea and was probably responsible for much of the intricate wall and ceiling decoration which still survives. The Domus Aurea also contains one of the first major examples of glass mosaic on a vault. His court sculptor, Zenodorus, created an astonishing bronze statue of the emperor, 35.5 metres (120 Roman feet) high, which stood at the entrance to the Domus Aurea. His patronage too must have stimulated the minor arts to judge by a passage in Pliny (Nat.Hist. 37.7.20) in which he is said to have paid 1 million sesterces for a single bowl.

When Nero became emperor, hostilities broke out with the Parthians over Armenia (ad 54). Domitius Corbulo captured Artaxata in ad 58 and statues and arches were voted in Nero’s honour (Tacitus, Ann. 13.41.4). There were some setbacks and an arch, decreed earlier, was set up in the middle of the Capitoline Hill (Tacitus, Ann. 15.18.1). Nothing now survives of it although it is shown on coins of ad 64 as a single arch with freestanding Corinthian columns and a gilded bronze quadriga (four-horse chariot) containing Nero accompanied by Pax and Victoria above the attic.4 In ad 59 as part of an initiative to remove commercial activities from the Forum Nero built a great market (macellum magnum) on the Caelian Hill (Dio, 62.18). Shown on a coin with the inscription MAC AUG on the reverse (Macellum Augusti, but less probably Machina Augusti, referring to Nero’s revolving room), it seems to have had a tholos (circular building) in the centre enclosed within a peristyle around which were rows of rooms or tabernae, an arrangement similar to markets at Pompeii and Pozzuoli.5 Tacitus mentions a vast amphitheatre erected by Nero in ad 57 (Ann. 13.31), although it was perhaps only a temporary wooden amphitheatre to replace the amphitheatre of Statilius Taurus, probably in the southern part of the Campus Martius. Awnings (vela) of sky blue and spangled with stars were hung on ropes in it (Pliny, Nat.Hist. 19.6.24). Nero’s architects/engineers, Severus and Celer, proposed a navigable canal from Avernus to the mouth of the Tiber, which was actually begun. Its length was to be 160 miles and its breadth sufficient to allow ships with five banks of oars to pass each other (Suet., Nero 31). This project was ridiculed by Tacitus as incredible, pointing out that the only water available to feed such a canal was in the Pontine marshes (Tacitus, Ann. 15.42).

The second great bath building, after that of Agrippa, was built NW of the Pantheon by Nero in ad 62 (Tacitus, Ann. 14.47). At the same time, he built a gymnasium at whose dedication in ad 62 Nero dispensed oil with Greek abandon (Tacitus, Ann. 14.47). The gymnasium was struck by lightning and burnt down in ad 62. The baths, and the gymnasium, if they formed part of the same complex as some scholars contend, were rebuilt in ad 63 or 64. The baths were said to be very luxurious and were also very popular. A plan made of the complex by Palladio, when portions of the building were still visible, has been shown to be broadly accurate by recent explorations in the cellars of buildings in the area of Palazzo Madama, Piazza S. Luigi dei Francesi and Piazza del Pantheon. However, the whole complex was rebuilt by Alexander Severus in ad 227 (SHA, Alex.Sev 25) and very few of the remains are Neronian to judge by Palladio’s plan, which shows a symmetrically arranged bathing complex of the Imperial type complete with natatio. There is no way of telling how much of this is Neronian and how far the original building lived up to Martial’s verdict: ‘What is worse than Nero? What is better than Nero’s Baths?’ (Martial, 7.34).

Nero resided at a number of residences in the vicinity of Rome. At some time before ad 60 he built a villa at Subiaco along both banks of the river Anio. Three complexes survive, but these represent only a small part of the original villa. The largest complex is on the north bank, linked by a great bridge to another complex on the south bank, which features a large curved niche. Tacitus tells the story of how Nero was almost struck by lightning while dining there (Tacitus, Ann. 14.22). In the monastery of S. Scholastica at Subiaco there is a portion of a barrel-vault from the villa, with rectangular, square and circular panels of polychrome glass mosaic set into a ground of pumice. The vault is reminiscent of the much larger vault in the triclinium of the Domus Aurea with an octagonal panel in polychrome glass mosaic set into a ground of pumice (see later). Another example of glass mosaic is on a niche found at Antium (Anzio) showing a seated Hercules which apparently dates to the time of Nero. Its decoration too is similar to that of the Domus Aurea. At Antium, which was his birthplace, Nero built a large villa where the Apollo Belvedere was found and a new harbour covering

60 hectares (148 acres) around which was a row of warehouses called the ‘grottoes of Nero.’

The first palace Nero built in Rome was the Domus Transitoria (passageway) because it linked the Palatine and the Esquiline (Suet., Nero 31). The imperial estates included the Villa of Maecenas on the Esquiline which had been bequeathed to Augustus. The main portion of the Domus Transitoria to survive is the so-called ‘Baths of Livia’, the name given to it by the excavators of 1721.6 It is a nymphaeum which owes its preservation to the fact that it was incorporated into the foundations of the Aula Regia of the Flavian palace. A pair of symmetrical staircases lead down to it (Figure 5.6). On the north side is a shallow semicircular recess pierced by a pair of niches each side of a stepped water cascade. In front of this, looking like the stage of a Roman theatre, is a row of nine low fountain niches ornamented with small free-standing columns which originally had bronze Corinthian capitals. Opposite was a dining pavilion supported on ten columns around three of its four sides and a small pool. At the sides were two barrel-vaulted rooms, each preceded by two columns. The paving and wall inlay were in polychrome marble, porphyry and serpentino. Some of the paintings on the

Figure 5.6  Rome, fountain court of Nero’s Domus Transitoria, destroyed in ad 64 and later incorporated

into the substructures of Domitian’s Palace: axonometric view. (After A. Boethius and J. B. Ward Perkins, Etruscan and Roman Architecture [Harmondsworth: Penguin, 1970].)

vaults have survived, forerunners of the paintings of the Domus Aurea. Delicate borders of relief stucco divide the vault and the lunettes into small panels which are filled with medallions, plaques and figured scenes surrounded by elegant scrolls studded with blue glass. One vault is finely decorated with octagonal coffers in white relief stucco. This small complex reflects Nero’s taste for refined opulence and hints at future extravagance. The palace was probably unfinished when it was destroyed by the great fire of ad 64.

The fire was the most terrible Rome had ever experienced. It began on 19 July in the Circus Maximus and in nine days completely destroyed three regions of the city, caused great damage to seven and spared only four. Nero was at Antium when the fire broke out and he returned to the city only when the fire was approaching the Domus Transitoria. The flames could not be prevented from overwhelming the Palatine, including his palace. It also seems to have destroyed a number of old and venerable buildings.

The Julio Claudian | Roman Architecture | Second edition | (Part-02)

The Julio-Claudians | Roman Architecture | Second edition | (Part-02)

The Julio Claudian | Roman Architecture | Second edition | (Part-02)


An immense number of mansions which had belonged to famous generals, still decorated with the spoils of war, were burnt; and temples of the gods, vowed and dedicated by the kings of Rome, and later in the Punic and Gallic wars; everything memorable and worth seeing from a former age that had survived (Suet., Nero 38).

Nero constructed emergency accommodation, threw open Agrippa’s public buildings, and even his gardens for the destitute, and brought food from Ostia and neighbouring towns.

However he earned no gratitude for this because there were rumours that the emperor himself had started the fire, and a story circulated that he watched the conflagration from the Tower of Maecenas and sang the Destruction of Troy on his private stage (Tacitus, Ann. 15.39). Although the rebuilding of Rome and the removal of refuse from the Ostian marshes took many years, it had a very positive effect on Roman architecture. First, brick-faced concrete emerged as a cheap and rapid method of building; and second, the new regulations enacted after the fire altered the city’s appearance for the better. Tacitus describes Rome at the time of the Great Fire (ad 64) as a city of ‘narrow winding passages and irregular streets’ which had encouraged the progress of the fire (Ann. 15.38). Now the dimensions and alignment of street fronts were regulated, the streets were broad, and the houses spacious. Their height was restricted, the fireproof stone was used, there were to be no party walls between buildings, and frontages were protected by colonnades. Vaulting was used instead of timber for ceilings, water was to be everywhere available, and fire fighting equipment was mandatory. Even so, some people lamented the lack of shade in the new city with its broad streets and reflected nostalgically on the narrow streets and high-built houses of the old city which were not so easily penetrated by the rays of the sun. All of this gives the impression that Nero’s new Rome resembled Ostia in terms of its building style and orderly layout. Tacitus praises Nero’s work of restoration (Ann. 15.43), although it was not completed on his death four years later or even on Domitian’s accession in ad 81 (ILS 3914).

Nero was not slow to take advantage of the destruction caused by the fire and immediately made plans for a vast new palace, the notorious Domus Aurea or Golden House. Suetonius’ description of it gives some impression of its splendour. A focal point of the park in which the Domus Aurea stood was the lake: ‘A lake, more like the sea than a lake, was surrounded by buildings looking like cities; as well as countryside with ploughed fields, vineyards, pastures and woods, filled with every type of domestic and wild animal’ (Suet., Nero 31). The grounds of the Domus Aurea covered 50 hectares (125 acres) and extended over the whole valley between the Esquiline, Caelian and Palatine hills. The park was so vast that a comic verse ran around Rome: ‘Rome will become a palace; migrate to Veii, citizens, unless the palace has reached Veii too’ (Suet., Nero 39). Such extensive grounds, which make it sound more like a villa than a palace, perhaps suggest as its model the Ptolemaic palace at Alexandria which occupied a quarter or a third of the city (Strabo, Geo. 17.1.8). Lucan’s description of its gilding and rich inlays is also reminiscent of the Domus Aurea (Lucan, Phar. 1.111–130). The park was approached from the Forum along the Sacred Way, which was straightened and lined with collonaded porticoes. At the end was a vestibule in which stood a gilt bronze statue with Nero’s features, 120 feet (35.52 metres) high, the work of the Greek sculptor, Zenodorus. The vestibule was so extensive that it was surrounded by a triple portico 1,000 feet (296 metres) long (Suet., Nero 31). After Nero’s death, the statue was not destroyed along with his other works, but was dedicated to the sun and became a sacred object’ (Pliny, Nat. Hist. 34.18.45).

A row of fountains was built against the west side of the platform of the unfinished Temple of Claudius, whose waters, supplied by a branch of the Aqua Claudia, cascaded into the lake. The most remarkable survival is an entire wing of the palace which was later incorporated into the foundations of the Baths of Trajan built largely on the high ground to the north (Figure 8.1). Its existence was not suspected until it was stumbled upon by accident in the late 15th century. Its discovery had a profound effect on Renaissance art and many famous artists climbed down to visit it, notably Pinturicchio, Raphael and Michelangelo, all of whom carved their names onto its walls. Raphael’s Vatican loggia was particularly influenced by the frescoes of Famulus, who was responsible for most of the paintings in the Domus Aurea.

He always wore his toga while painting and because he worked only a few hours each day practically his whole output is in the Domus Aurea (Pliny, Nat. Hist. 35.37.37). Nowadays the rooms are damp and gloomy, the walls mildewed and the paintings faded. In these dimly lit rooms, it is difficult to imagine the former splendour of the great palace. Yet in terms of art and architecture, the building was undoubtedly revolutionary.

Its exterior must have resembled the many villas depicted in Pompeian paintings, because one or two column bases still survive (no. 1 in Figure 5.7) indicating that, like them, it had a columnar facade. A glance at the ground plan shows up many of the building’s strengths and weaknesses. For example, the octagonal room (16) is undoubtedly a piece of architectural ingenuity. However, its bold shape creates an architectural jumble behind it. Similarly, the main suites opening off the big five-sided courtyard in the middle of the façade (12) are well-designed and in each case, the middle room is given greater prominence than the flanking rooms. Yet once again there is a jumble of awkward-shaped rooms behind. The architects/engineers, called Severus and Celer (Tacitus, Ann. 15.38-43), showed their skill in good groupings, rhythms and novel solutions, but not in overall planning. However, it may be that they had to contend with an earlier building on the site which may be represented by the oblique wall running at a NE angle from the centre of room 9. The block of seven rooms south of courtyard (6), which were perhaps bedrooms, show the best organisation. The shapes and sizes of the rooms repay close attention. They are alternately wide (2 and 4) and narrow (5) with a particularly wide room in the middle (3). This room and the two rooms next to it have a square-sided recess, presumably for a bed. The recesses in rooms 2 and 4 face south, whereas the recess in rooms 3 faces north towards the courtyard. The rhythm continues in the lapsed room (5) and the room corresponding to it on the west side. There is a further rhythm in the way the rooms are alternately short and long. The cryptoporticus (7) on the north side of the courtyard (6) is also interesting. Because it was built against the hillside it had the dual function of the corridor and sustaining wall.

Also opening off courtyard (6) was a large barrel-vaulted triclinium or dining room (8) whose lunette would have towered over the peristyle of the courtyard to light the rooms behind. At both ends, it had a screen of columns. At the far end was a nymphaeum, a barrel-vaulted room (9) much smaller than the triclinium with a fountain at the end. Covering the upper parts of the walls and extending to the springing of the vault was a mosaic frieze, 2.20 metres high, which ran unbroken around the walls of both the larger and the smaller barrel-vaulted rooms, a total length of 65.84 metres. It was bordered at the top and bottom by a row

Figure 5.7  Rome, Domus Aurea or Golden House of Nero, ad 64–68: plan

of cockle shells. The vault of the smaller barrel-vaulted room was covered in brown pumice to give the appearance of a rustic grotto. In the centre of the vault is an octagonal panel filled with a mosaic of polychrome glass tesserae showing Odysseus offering wine to the Cyclops. The idea of a cave glimpsed through a garden peristyle is not new, but the ensemble, like Tiberius’ grotto at Sperlonga, is another outstanding example of the skill of Roman architects in introducing nature into a domestic setting

The five-sided courtyard (12) used to be seen as the focal point of the wing as a whole. However, a second courtyard has been found to the east which suggests that the wing was longer than previously thought and that the octagonal room (16) was its centre. The colonnade may have continued around the courtyards or perhaps the courtyard contained a building with somewhat taller columns in the manner of villas depicted in Pompeian wall paintings, for example, the House of Lucretius Fronto. Immediately behind the centre of the five-sided courtyard is a large vaulted room (11) flanked on each side by a symmetrical suite of lesser rooms. The large room was called the room of gilded ceiling because of the painted and gilt coffered panels made of moulded relief stucco which decorated its vault. The vault is the one Raphael and other artists clambered through to make the drawings which inspired so much Renaissance stucco work.

The group of rooms to the east of the five-sided courtyard is centred around a large octagonal domed room (16). Here the architect had two problems. The octagonal room and the rooms which opened off it created a series of awkwardly shaped triangular and irregular rooms behind. Second, the building ran very much closer to the hill on the east side than on the west. The result was that there was no room for a courtyard to balance that on the west side. Instead, the cryptoporticus (14) abutted directly onto the rooms behind the octagonal room. These rooms were therefore not only awkwardly shaped but also badly lit. The architect to some extent overcame the problem by ingeniously piercing downward sloping light wells into the upper part of the northern wall of the cryptoporticus and opening a corresponding set of light wells lower down in the southern wall opposite. In this way shafts of light were directed from the edge of the hill into the rooms immediately south of the cryptoporticus. An equally ingenious device was used to convey water for the waterfall in a room (15) which opened off the octagonal room. Water from the top of the hill was ducted across the cryptoporticus via an arched bridge.

The octagonal room (16) is perhaps the most revolutionary architectural concept in the whole house. Its domical vault, which was cast in horizontal layers of opus caementicium, is supported on eight brick-faced concrete piers, originally adorned with stucco and marble pilasters (Figures 5.8 and 5.9). Although it begins as a domical vault, it becomes a hemispherical calotte higher up, with an unusually wide oculus. The dome is stabilised by the five radial rooms surrounding it, whose sides form a series of triangular pillars connected to the dome by prismatic wedges. The surrounding radial rooms are lit from five light wells over the extrados of the dome (Figure 5.8). The result is that, if one stands under the dome, the radial rooms are bathed in light, although the oculus appears to be the only light source.

For a long time, there was speculation that the upper storey of this room was the circular dining room described by Suetonius whose roof revolved slowly, night and day like the heavens (Suet., Nero 31). However, in 2009 a tower-like room was found in the Vigna Barberini on the slopes of the Palatine Hill overlooking the Colosseum, which may be the room in question. The room is circular, 16 metres in diameter, and surrounded by a wall more than 2 metres thick. The dining part is reconstructed as a circular open-air room whose roof is supported by eight columns and whose circular floor is rotated. The mechanism is below the floor.

Figure 5.8  Rome, Domus Aurea of Nero, octagonal room, ad 64–68

Figure 5.9  Rome, Domus Aurea of Nero, ad 64–68, octagonal room: axonometric view from below, section and plan. (After A. Boethius and J. B. Ward Perkins, Etruscan and Roman Architecture [Harmondsworth: Penguin, 1970]).

In the centre stands a 4-metre-wide pillar with two sets of eight masonry arches connecting it to the wall, one above the other. Combined with the outer walls the two sets of arches create a very stable structure. The structure survives only to this height because the upper part, the dining room itself, has been dismantled and everything of value removed. A close examination of the tops of the upper eight arches, which radiate like the spokes of a wheel, reveals that exactly in the centre there is a cavity 0.30 metre deep and 0.16 metre wide. This is thought to have held the pivot around which the floor above revolved. On the top of each alternate arch are five cavities, making 20 in all. These are thought to have encased bronze spheres, in effect the ancestors of modern ball-bearings. Very fine clay found in the cavities served as a lubricant so that the spheres could turn without coming out of their slots. This suggests that there was a circular moving floor above that could rotate around the central pivot. The moving floor is reconstructed as a complex work of carpentry, covered perhaps with marble paving. To make the floor rotate some sort of mechanism would have been required. The excavators claim to have found traces of this mechanism and suggest that water was the power source, as lime deposits were found on certain stones. Certainly, a branch of the Claudian aqueduct, called the Aqua Neronis, reached the Palatine near here and part of it is still visible where it crosses Via di S. Gregorio. It is therefore conjectured that a large water wheel was activated by the aqueduct and its force was transmitted using shafts and gears to the mobile floor, turning it at a slow and regular speed. Little survives of this mechanism apart from imprints of metal objects and an iron fixture set into the masonry, because any metal was salvaged when the building was abandoned. This ingenious complex was uncovered by a team of French and Italian archaeologists.

The Domus Aurea was Nero’s greatest architectural achievement and one which was to have a profound influence on future Roman concrete structures. The work was done in haste, as the poor quality of the bricklaying and the thick mortar joints shows. Ironically it is noticeable that the brick facing of the substructures of Trajan’s Baths, which frequently cut across the Neronian walls, is easily distinguishable because it is more finely laid, even though it was never intended to be seen. Significantly, the builders of the Domus Aurea chose brick as a facing material instead of opus reticulatum because it was recognised as a material suited to rapid construction. Second, the Domus Aurea is significant because of its novel, some would say revolutionary, use of concrete. It is an architecture in which interiors become more significant than exteriors and, to use an expression of John Ward Perkins, ‘the emphasis has suddenly shifted from the solids to the voids.’7 It was an architecture where space, light and dramatic effects were of the greatest importance. Third, Nero’s reign was of great significance because of the methods used in the rebuilding of Rome after the fire of ad 64. The new fire regulations produced an urban landscape very different from the old one, with its tortuous alleys and precarious tenement blocks which once provoked the ridicule of the Campanians (Cicero, De lege Agraria, 2.96). Although very little is known of the appearance of Nero’s new Rome it can perhaps be imagined by looking at the tall apartment blocks of brick-faced concrete built a few decades later in Ostia. These buildings with balconies, open courtyards and rooms with vaulted concrete ceilings, ranged along broad straight, paved streets may give some impression of the appearance of the newly rebuilt capital. In Rome itself, the only street which gives some idea of Nero’s new Rome is Trajan’s Markets (Figure 8.5).

The career of this extraordinary emperor ended abruptly in ad 68 when his Domus Aurea was scarcely complete and the reconstruction of Rome cannot have progressed very far. He was forced to flee the city and only a few kilometres away on the Via Cassia he committed suicide. His dying words, ‘What an artist dies in me!’ (Suet., Nero 49), are perhaps a fitting epitaph for his reign. The caprices of Nero and his predecessors had fostered much innovation in art, architecture and engineering. Indeed the architectural developments which took place during the reign of Nero could well be described as revolutionary, and as such had far-reaching consequences for the future of Roman architecture.




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