The temple was an apsidal hall facing onto a large rectangular enclosure measuring 110 × 135 metres and surrounded by colonnades. The six columns of the temple façade were on the same line as the surrounding colonnades and were distinguished from the latter only by being higher. The apsed hall of the macellum at Pozzuoli had a similar relationship to the colonnade and we may see an echo of this treatment in the garden façade of the House of the Stags at Herculaneum. Presumably the lower entablatures of the flanking colonnades would have been carried on brackets projecting from the taller columns of the temple, in the manner of a Rhodian peristyle such as are found, for example, in some Hellenistic houses at Delos. The complex was built in what was at the time the only remaining free space in the area north-east of the Forum. The area was more congested than it seems today because until the time of Domitian a spur of land linked the Capitoline hill with the Quirinal and ran close to the Forum Julium and the Forum of Augustus, and another spur ran from the Palatine across to the Esquiline immediately to the south of the Temple of Peace (the latter spur, the Velia, was cut away in 1933 to make way for the road now known as the Via dei Fori Imperiali). On the site of the Temple of Peace there had formerly stood a meat market (macellum), but Nero had recently built a new market on the Caelian hill. As the Temple of Peace closely resembles meat markets such as those at Pompeii and Pozzuoli in layout it is possible that it may have followed the old market's plan to some extent.

But these buildings, although important to the urban layout of Rome, must take second place to that most important of Vespasian's buildings, the Flavian amphitheatre or Colosseum (the name 'Colosseum' dates from the eighth century AD and refers to its size, or possibly is a confusion with the colossal statue of Nero which stood close by). It was built on the site of the lake of Nero's Golden House, a master stroke, as Vespasian was seen to be creating a place of public resort out of a tyrant's palace. Also, the sub-soil was very firm and compact and thus ideal for the huge weight of the building which measures 188 × 156 metres × 48.5 metres high.

t was the first large permanent amphitheatre in Rome, although gladiatorial spectacles had been popular in the city for over 300 years. It is estimated to have had a capacity of 45,000-55,000 spectators. The façade, built of travertine, has 80 arched openings at ground level, flanked by Tuscan half-columns. Above are two further tiers of openings also decorated with half-columns, Ionic and Corinthian respectively, and the top storey is decorated with Corinthian pilasters flanking alternate square openings and plain walls, originally decorated with bronze shields. Immediately behind the lowest three storeys are two rings of annular passageways from which run radial passages leading to the main annular passage. Further radial passages lead on to the innermost annular passage.

The system of circulation was exceptionally clear and logical. A fine triple entrance on the south side gave access to the consul's box, which was situated at the edge of the arena in the middle of one long side; a similar entrance on the north side gave access to the emperor's box which faced the consul's. The gladiators entered from one of the short sides and the bodies were carried out through the Porta Libitinaria opposite. Each of the 76 entrances had a number carved over the arch. Admission was by ticket and the use of wooden barriers would have ensured orderly circulation throughout the building. The door by which the spectator entered determined the segment in which he would sit. Women, banished by the Lex Roscia (67 BC) to the highest seats at the back of theatres and amphitheatres, would have gone no further than passage B where staircases would take them directly up to their rows of seating within that segment (section 4). Men of the lower ranks could proceed to passage A where staircases would take them to the upper block of seating (section 3) above the big annular gallery which separated the upper classes from the lower. Men of higher rank proceeded up the staircases on the opposite side of the passage to reach the lower block of seating (section 2). Those of the highest ranks, including knights or senators, would have proceeded straight through to the innermost annular passage, C, where a small ramp led them to the arena-side seats.

The materials needed to build this vast structure included 100,000 cubic metres of travertine alone. It is calculated that 300 tons of iron were needed to clamp the blocks together. An army of masons, blacksmiths, bronze workers, marble workers, and construction workers must have been engaged on the building. It has been suggested that the Colosseum was built by captives from the Jewish war. However, the structure of the building is so complex that an unskilled labour force could hardly have been used on the building itself, although such men could have been used in ancillary occupations such as transporting the stone from the Tivoli quarries (it is calculated that up to 200 ox-carts of stone entered Rome each day during the period of its construction). A more real problem is how such a building could have been inaugurated by Titus in AD 80 although it could not have been started by Vespasian until AD 75.

An answer has been given by penetrating analysis of the building by the Italian engineer, Giuseppe Cozzo. Cozzo showed that the enormous number of workmen required to build such a vast structure in so short a time could not physically have worked on the building at the same time if it was built by conventional methods. Therefore the architect must have worked out a method of erecting a skeleton structure in many ways analogous to modern concrete or steel-framed buildings. Cozzo shows that only the two lowest orders of the exterior were actually completed by the time of Vespasian's death, and that only the barest skeleton of the building was finished by that time (fig. 79). The method of work was to erect the outer travertine walls up to the top of the second order and the two concentric walls behind them. In the radial passages leading towards the arena Cozzo has isolated a number of travertine piers which run straight up through the structure quite independently of the walling between them. When these piers reached the point where they were to support the vaults which carry the sloping staircases a concealed springing was left in the stone. Instead of building the vault at this stage the pier was continued until it had reached its highest projected point, i.e. where it supported the seating. When the piers reached their full height the topmost vaults were built, but not the lower ones. Next, brick arches were built linking the piers and on these were constructed the sloping barrel vaults which supported the banks of seats. Thus, in a very short time, a covered skeletal structure was put up. Meanwhile, further gangs of men could be employed filling in the spaces between the piers, building staircases and the lower sets of vaults on the springings provided. An advantage of this mixture of materials in the interior is that it extended the working season. Unlike masonry, which can be quarried and worked at any time of the year, concrete is adversely affected by extremes of temperature, and in particular below about 10° C the time taken for it to set increases and the strength obtained decreases quite remarkably. The Romans were quite aware of this, as Frontinus says they could only repair the aqueducts between 1 April and 1 November (de aquis, 123).

Probably work on the infilling and building of staircases had begun by the time Titus succeeded his father as Emperor, and Titus also built the third tier of the façade. The fact that the vaults at the level of the top of the second storey had been built immediately had a dual advantage. Firstly, the workmen busy on the infilling could work under cover. Secondly the top of the vault provided a flat platform on which materials for the upper parts of the building could be stored. Only the actual façade wall was built by Titus and not the concentric walls behind. This was because no vaulting could be built on the third tier at this stage. The reason for this was that scaffolding had to be built to support the topmost parts of the building. On the inner side of the piers of the third storey huge projecting corbels were left to support the scaffolding on the inside of the building. Despite the fact that coins of the period show four rows of arches it is probable that only three tiers of arches were actually completed when the building was inaugurated by Titus in AD 80.

The inauguration was accompanied by a sea-battle held in the old naumachia, built by Augustus near the Tiber according to Suetonius (Titus, 7. 3). This passage has often been taken to mean that the Colosseum itself was flooded for sea-battles, an interpretation based on the assumption that the Colosseum arena was solid at the time of the inauguration and that the rooms below the arena floor were built at a later date. Yet the only literary authority to state that the sea battle was actually held in the Colosseum is Dio Cassius (Ep., 66. 25) and this is very possibly a confused account. It does however make good sense to suppose that the rooms below the arena were a later addition because the flat arena floor would have been an ideal place for the storerooms, huts and masonry dumps which would have been needed during the building operations.

Domitian completed the building, adding the topmost storey of the façade. In alternate bays there was a big bronze shield, and a square window. Cozzo suggests that the smaller square openings at the bottom of the bays containing the shields were used in the construction period to support the transverse beams linking the outer and inner tiers of scaffolding. Domitian built the topmost storey of seating, summum Maenianum, of wood, presumably so that the thrust should not be too great.

Domitian was probably responsible for the maze of substructures under the arena. Around the edge of the arena are 32 cells in which the animals were kept. The system of caging the animals and bringing them up to the arena at the right moment well illustrates Roman ingenuity in spite of limited technology. The animals were brought in by means of underground passages under the short ends of the arena. Each segment underneath was completely separate and contained eight cages close to the edge of the arena. The animals were driven along a narrow passageway only 55 cm wide which did not allow them to turn around. Handlers could manipulate the cell doors so that they went into the correct cells, and then the doors of the cells were shut.

Inside the cell was a cage which consisted of a bottom, three sides and a top to which was attached the tackle for hauling it up to the upper level. The cell door itself provided the front of the cage and prevented the animal escaping. The projecting brackets above the cell served the double purpose of supporting the posts of the safety net at arena level and carrying the wooden beams of the intermediate floor below arena level. In the back of the upper part of each cell was a small room in which the beast handlers took up their positions immediately before the animals were due to appear in the arena. Here they could control the tackle designed to hoist the cages up to the upper part of the cell. The system was a very neat one because the handlers could move about in perfect safety on the upper level while the animals were down below. Then at the given signal they took up position in their small rooms at the back of the cell and hauled the animal up. As the cage had only three sides the animal was free once the cage reached the upper level. Its only way of escape, however, was into a narrow passageway corresponding to the 55 cm passage along which it had been driven below. Iron gates no doubt prevented the animal wandering to the next cage. Its instinct would lead it to rush up the ramp and through the trapdoor into the light of the arena above. The operation must have been conducted very quickly and quietly. In a well-managed show all 32 animals would appear in the arena practically simultaneously.

If the animals could appear so rapidly in the arena, the scenery, which was a conspicuous feature in the centre of the arena, could appear and disappear with equal efficiency. The secret was a series of huge hinged platforms in the middle of the arena. Vast sloping masonry supports can still be seen in the wide gallery running through the middle of the arena. On these were built great hinged wooden platforms, pegmata, on which the scenery was mounted. They were designed so that the hinged end was immediately below arena level and the other end was about five metres below arena level. Thus, scenery up to five metres high could be built. Also, the slope meant that the effort required to haul the platform up to arena level was not very great, especially with the aid of counter weights.

One final feature of the Colosseum which is never mentioned by ancient authors is the huge velarium or canvas awning which protected the spectators from the heat of the sun. Such velaria are known to us from paintings like that of the amphitheatre at Pompeii, and were a common feature of theatres and amphitheatres. It will be noticed that in the topmost storey of the façade there are three projecting brackets in each bay, making a total of 240 for the whole circumference. The modillions which crown the parapet alternate with these and there is a vertical hole in the cornice between each modillion corresponding to the bracket below. Huge wooden poles were inserted into these holes and rested upon the brackets. The poles probably projected a considerable height above the top of the masonry. To these poles was attached the rigging which supported the velarium. The procedure for raising the velarium was as follows: a great rope ring was laid down in the middle of the arena corresponding to it in size, and attached to this were the supporting ropes which were threaded through pulleys on the masts. These ropes ran down to the bollards at pavement level, some of which can still be seen on the north-east side of the building. On each bollard was a winch around which the rope passed. The ropes were finally secured to a series of capstans around the building. At a given signal the ropes were tightened and at the beat of a drum the ring was slowly raised into position. When the ring was in position further ropes were joined to it lower down and the strips of canvas which formed the velarium were unrolled on to the rope network beneath. A contingent of 100 sailors from Misenum was permanently billeted nearby to maintain the rigging. When it was periodically lowered and raised at least 1,000 men would have been needed. There must have been a clear space all round the building between the velarium and the top of the masonry which would prevent the awning being torn to pieces by high winds. Even so, the noise of the velarium on windy days must have been deafening, especially combined with the roaring of the animals in and under the arena.

Thus the Colosseum is not just an architectural masterpiece, but in terms of planning, engineering and organization it must rank as one of the most astonishing achievements of antiquity. Nor must we look at the building in isolation. When we consider that it sat in the middle of a complex of ancillary buildings including the quarters of the sailors, the barracks for the gladiators with its small practice arena in the centre, and the host of taverns, wine stalls, refreshment booths and the public baths built by Titus, one cannot but marvel at the creators of such a complex.

Vespasian was succeeded by his elder son, Titus, who in his short reign endeared himself to the Roman people as one of the best-loved Roman Emperors. He inaugurated the Colosseum in AD 80 and built the nearby baths which bear his name. Little of the Baths of Titus now survive, but the plan is known from a Palladio drawing. The drawing shows a building which is entirely symmetrical. The largest room, the frigidarium, is a basilical hall with a semicircular apse in the middle of one long side and four plunge baths. At either end is a palaestra. Passing through a small tepidarium one reaches a pair of caldaria. On the south side are the usual hot rooms and there is a large open space to the south of the bathing block for gymnastic exercises. Although the building is only about a quarter of the size of the great Imperial thermae of the second and third centuries, it has most of the elements of these larger baths. The main element which is lacking is the natatio or open-air swimming pool which in the classic great baths (e.g. the Baths of Caracalla) would be situated to the north of the frigidarium and flanked by apodyteria or changing rooms. However, the Baths of Titus have come a long way from the Stabian Baths at Pompeii and are only a short step away from the fully developed great thermae. Such a dynamic scheme bears the stamp of the new architecture as seen in Nero's Golden House. The fact that the baths are exactly aligned with the latter gives rise to the speculation that the Baths of Titus may be a remodelling of the famous baths of the Golden House as described by Suetonius.

Credits:

From: Roman Architecture

Book by Frank Sear; Routledge, 1998. 288 pgs.