Etruscan and Roman Architecture
The Greek colonies in Sicily and southern Italy were a natural source of architectural inspiration to the other peoples of Italy, and architectural development in etruria and central Italy is in some ways a process of increasing approximation to the forms and materials of Greek architecture. Most Etruscan buildings were of non-durable materials, and although some houses are now known, the chief building types to be considered are tombs and temples. From c. 650 BC onwards, the Etruscans, unlike most Greeks, constructed elaborate underground tombs for their dead, the forms varying both with area and date. Many early tombs have corbelled chambers with a tumulus above; later the tomb chambers are more commonly rock-cut. At Tarquinia they are elaborately painted, at Cerveteri (Caere) often carved in relief. The ceiling frequently portrays a heavy timber roof structure in paint or relief. After c. 400 BC there was a fashion for elaborate rock-cut facades in some cities (e.g. at Norchia). The tradition of Etruscan tomb design affected Roman architecture when a monumental tomb was required (e.g. the Mausoleum of Augustus, 28-23 BC).
City walls, of which many remain dating from c. 6th century BC, contain arched gates. Some of the latter were later rebuilt (e.g. Falerii Novi, c. 250 BC; Perugia c. 100 BC). The source of the arched form is not known but is believed to have come from Asia Minor or Phoenicia.
Etruscan temples were related to the Greek type (see temple. classical), but were set upon a high podium and so had a portico only at the front; this formed a deep porch, almost as large as the cella building, and in the latter three cellae might be set side by side. The walls were of mud brick; the columns were of wood and so are lost, but stone versions in tombs show free and varied adaptations of the Greek columns, not a 'Tuscan Order' (see orders of architecture). The most impressive feature of a temple was normally its roof, with painted terracotta sheathing the wooden beams, elaborate relief decoration at the eaves, and often a row of statues along the ridge.
This Etruscan type of temple influenced the architecture of Rome and central Italy, and the capitol, begun when Rome was under Etruscan domination, was virtually an Etruscan temple. In the last two centuries BC stone, then marble, replaced terracotta, wood, and mud brick, and conventional Ionic and Corinthian (rarely Doric) were adopted, but the podium and frontal emphasis were retained (e.g. temples of Hercules at Cori and 'Fortuna Virilis' at Rome, both late 2nd century BC). This rather conservative, formal trend in Roman architecture culminated under Augustus (31 BC-AD 14), by which time the lessons of Hellenistic architecture had been fully digested.
However, temples are not the most striking monuments of Roman architecture. Much more characteristic are the baths (thermae), basilicas, palaces, amphitheatres, markets, aqueducts, and other types of building, almost all of which involved arches and vaults (always semicircular, never pointed), rather than the Greek system of vertical supports and horizontal beams. The acceptance of this new structural system was made easier by the weaker tradition of the Greek orders in Italy, and by the development of a new material, concrete, which allowed the formation of curved planes, arches, vaults and domes much more easily than with the accurately cut stonework of the Greeks.
Roman concrete was a mixture of lime and volcanic sand with water, used to bind lumps of stone aggregate. Its strength was improved with experience until it was an immensely strong building medium which set even under water. Vaults and foundations were formed in wooden shuttering, but walls above ground were normally built with an integral facing; initially small pyramids of stone were used, but thin triangular bricks are characteristic of mature Roman architecture, giving the appearance of a completely brick wall, as in the tenements of Rome and Ostia. The facings were not load-bearing, however, and were chiefly valuable while the concrete dried and in controlling cracks formed by settlement.
Both vaulting and concrete were used cautiously at first, but from c. 200 BC they occur in strictly functional buildings (e.g. the Porticus of Aemilius at Rome, c. 174 BC). The Tabularium (record office) at Rome, 78 BC, is an early example of the orders used decoratively with arches in a facade of some importance, but the new-methods did not play an important role in architecture designed to impress until the mid 1st century AD. The Golden House of Nero (AD 64-68) and the Palace of Domitian on the Palatine (AD c. 82-92) are notable for their complex room shapes and intriguing vaults, made possible by the use of concrete. The pantheon, more sober though equally sophisticated, is another prime example of how the new methods changed the nature of architecture. Apart from the rather conventional entrance portico, the exterior is unimportant; it is the huge domed interior space which makes the building, thus reversing the normal Greek emphasis on mass. The span of 43-20 m is more than two and a half times the maximum achieved by the Greeks, and remained unsurpassed for 17 centuries. The use of the Greek orders in the Pantheon is also characteristically Roman; they do not carry loads, but articulate, give scale, and create illusions. Another group of buildings illustrating the achievements of mature Roman architecture are the thermae with their complicated symmetry, their huge vaulted halls articulated by conventional columns, and their untidy exteriors.
Peace and prosperity under the empire led to a great outburst of building in the provinces, especially in the 2nd and early 3rd centuries AD. In the western provinces architecture largely reflected ideas from Rome, although the new vaulted architecture, dependent on a volcanic sand available only in central Italy, could not be repeated. The eastern provinces were creative as well as receptive, however. New ideas like the colonnaded street, as at Palmyra, were developed from Hellenistic architecture and ideas received from the west were modified and returned. Load-bearing columns were more widely used, but vaulting in brickwork was also developed, and became the standard technique of byzantine architecture.
The quality of Roman concrete was still undiminished in the early 4th century AD, and the Basilica Nova of Maxentius and Constantine is a building in the high imperial tradition. However, there was an increasing tendency for the vaulted structure to be lightened, so that the supporting piers became more obvious, and both exterior and interior came to be dominated by large windows (e.g. in the Basilica at trier, early 4th century AD). The Greek orders were thus less important, and when they Here used, it was often illogically, as in the Golden Gate of Diocletian's palace at Split (AD 300-306). Constantine's removal of the capital to Constantinople in AD 330 made architecture more susceptible to influences from the eastern provinces, and few major buildings were thereafter built in the Roman west.