The Janus Geminus, often interpreted as the embodiment of duality, housed an ancient bronze statue of the deity Janus, believed to have been established by Numa Pompilius, the second king of Rome, as recounted by Plutarch. According to Pliny the Elder, the sculpture featured fingers positioned to represent the 355 days of the year, while Ovid depicted it with one hand clutching a key, symbolizing Janus’s role as the deity of doorways, and the other grasping a staff, illustrating his guidance and authority.
The gates of the Janus Geminus served as indicators of Rome’s martial status—open during wartime and closed during peace negotiations. Throughout history, these doors were reportedly shut only three times: after the first Punic War in 235 BC, post the Actium battle in 30 BC, and during various occasions under Augustus’s reign. The interpretation of the doors’ significance shifted over time: Ovid poetically suggested that peace was confined within when the doors were shut, while war remained outside, and in contrast, at times, the opposite was depicted. Janus’s depiction of either safeguarding or prioritizing war reflected the tumultuous nature of Rome’s conflicts.
Despite the lack of archaeological confirmations regarding the Janus Geminus’s site, numismatic sources reveal its design as a rectangular structure with arched entrances on either side, bordered by columns. Its location was reportedly between the Forum Julium and the Forum Romanum, near the Argiletum. Historical accounts do not suggest it was ever reconstructed, but it likely had to be relocated for the Basilica Aemilia’s construction in 179 BC and later during Domitian’s rebuilding efforts of the Curia Julia around AD 94, where a new four-sided statue possibly replaced the older one.
In the period leading up to Pertinax’s assassination in AD 193, a new bronze shrine was erected in front of the Curia, adequate to accommodate a large image of Janus. Procopius noted that by that time, the ancient practice of opening the gates in times of war had been supplanted by evolving Christian beliefs.
Janus was revered in Roman culture as the deity governing transitions, whether physical or temporal. His name is etymologically linked to terms for archways and entrances, highlighting his role as the divine gatekeeper. He was pivotal in rituals, being the first deity invoked in prayers, thereby serving as the passageway for supplicants’ appeals to the divine. Represented with four heads looking towards the cardinal points, Janus’s dominion over all territories emphasized his omnipotence. The restructuring of the Roman calendar later attributed 365 days to his fingers.
A sestertius issued during Nero’s reign celebrated the conclusion of an indecisive campaign against the Parthians, featuring an image of Janus’s edifice built from ashlar stone with embellished windows and perhaps a flat roof. This version displayed doorways framed by columns with a hanging wreath, signifying the geminae belli portae through which significant military processions, as documented by Virgil, would pass. The inscription celebrated the peace attained by the Roman people on land and sea, acknowledging Janus’s doors were shut; however, shortly thereafter, they would reopen with the onset of the Jewish War in AD 66.
References: Ovid: Fasti (2000); “The Curia Julia and the Janus Geminus” (1978) by Lawrence Richardson; The Historical Topography of the Imperial Fora (1984) by James C. Anderson; Brill’s New Pauly: Encyclopaedia of the Ancient World (2002-) edited by Hubert Cancik and Helmuth Schneider; Statius: Silvae (2003); “The Shrine of Janus Geminus in Rome” (1943) by Valentine Müller.
