Samuel Ball Platner, Thomas Ashby, A Topographical Dictionary of Ancient Rome

IANUS QUADRIFRONS, TEMPLUM

erected by Domitian in the forum Transitorium (Mart. x. 28. 3-6; xi. 4. 5-6; Serv. Aen. vii. 607; Lydus, de mens. iv. I; Macrob. i. 9. 13), in which he placed the four-faced statue that was said to have been brought to Rome from Falerii in 241 B.C. The shrine was square with doors on each side, and the statue of the god was said to look out on four forums (Mart. loc. cit.), i.e. the fora Romanum, Augustum, Pacis, Transitorium. It is not known whether this four-faced statue from Falerii had anything to do with the Roman Janus or not, or whether it had been housed in a shrine before Domitian's time. It was standing in the sixth century (Lydus, loc. cit.; Jord. i. 2. 347, 450; WR 106; Rosch. ii. 25-26; Mem. L. 3. xi. 26-32; Burchett, Janus in Roman Life and Cult, Menasha, Wis. 1918, 40).