The Arch of Constantine, according to the Enc. Brittanica: (AD 312), one of three surviving ancient Roman triumphal arches in Rome. Erected hastily to celebrate Constantine's victory over Maxentius, it incorporates sculptures from many earlier buildings, including part of a battle frieze and figures of prisoners from the Forum of Trajan, a series of Hadrianic roundels, and a set of eight Aurelian panels.