The great revolution in Roman architecture is generally dated from the time of Nero's Domus Aurea (64-69 AD). But the expanded repertory of architectural shapes and procedures that was the foundation of that revolution first began to come together in the time of the Republic. Increased wealth and important political changes created a growing demand for architectural projects of all sorts. Simultaneously, the expansion of Roman power brought more Greek influences directly to Rome. Then, when the development of the potential of concrete construction made Roman innovations in vaulting and domes possible, architecture sped forward. The decades prior to Sulla's brief reign as dictator were particularly productive ones for architecture. But the subsequent periods of civil war and the emergence of an old-fashioned official taste under the influence of Vitruvius resulted in the advances of the earlier period being temporarily set aside. The Augustans razed most of the secular public architecture of the Republic and rebuilt much else. Of the Republican architecture that has survived, the most impressive monumental work is the sanctuary of Fortuna Primigenia (c. 80 BC) at Praeneste (later Palestrina). This gigantic complex offers a "prophetic blend" of the new uses of concrete, vaulting and arches, hinting at the certain eventual decline of the dominance of trabeated design and construction (Kostof 206). The study of the Praeneste complex demonstrates that the Neronian architectural revolution had been in the making for at least the previous two and a half centuries.
The second century BC was a time in which "direct exposure to influences from the Hellenistic East and the already Hellenized Campagna" had increased enormously (Fletcher 212). Under this influence the Romans began to exploit the travertine and tufa that was available to them locally and to import marbles of various types from abroad. The classical orders of Greece,...