considerable time after the initial triumph of Christianity under Constantine. The decline of Roman religion was relatively slow, and the temples themselves were not appropriated by the government until a decree of the Emperor Honorius in 415. Santi Cosma e Damiano, in the Roman Forum, originally the Temple of Romulus, was not dedicated as a church until 527. The best known is the Pantheon, Rome, which, however, is highly untypical, being a very large circular temple with a magnificent concrete roof, behind a conventional portico front. Terms The English word "temple" derives from the Latin templum, which was originally not the building itself, but a sacred space surveyed and plotted ritually. The Roman architect Vitruvius always uses the word templum to refer to the sacred precinct, and not to the building. The more common Latin words for a temple or shrine were sacellum (a small shrine or chapel), aedes, delubrum, and fanum (in this article, the English word "temple" refers to any of these buildings, and the Latin templum to the sacred precinct). Architecture The form of the Roman temple was mainly derived from the Etruscan model, but in the late Republic there was a switch to using Greek classical and Hellenistic styles, without much change in the key features of the form. The Etruscans were a people of northern Italy, whose civilization was at its peak in the seventh century BC. The Etruscans were already influenced by early Greek architecture, so Roman temples were distinctive but with both Etruscan and Greek features. Surviving temples (both Greek and Roman) lack the extensive painted statuary that decorated the rooflines, and the elaborate revetments and antefixes, in colourful terracotta in earlier examples, that enlivened the entablature. Etruscan and Roman temples emphasised the front of the building, which followed Greek temple models and typically consisted of wide steps leading to a portico with columns, a pronaos, and usually a triangular pediment above, which was filled with statuary in the most grand examples; this was as often in terracotta as stone, and no examples have survived except as fragments. Especially in the earlier periods, further statuary might be placed on the roof, and the entablature decorated with antefixes and other elements, all of this being brightly painted. However, unlike the Greek models, which generally gave equal treatment to all sides of the temple, which could be viewed and approached from all directions, the side