In ancient Roman religion and myth, Janus is the god of beginnings and transitions. He is usually depicted as having two faces, since he looks to the future and to the past. The opening month of the year (January, from janua, “gate”) was sacred to him, as was the first day of each month. The Romans named the month of January (Ianuarius) in his honor.
Janus presided over the beginning and ending of conflict, and hence war and peace. The doors of his temple were open in time of war, and closed to mark the peace. As a god of transitions, he had functions pertaining to birth and to journeys and exchange, and in his association with Portunus, a similar harbor and gateway god, he was concerned with travelling, trading and shipping.
Janus was constantly encountered in religious ceremonies throughout the year, and was ritually invoked at the beginning of each one, regardless of the main deity honored on any particular occasion.
Janus frequently symbolized change and transitions such as the progress of future to past, from one condition to another, from one vision to another, and young people’s growth to adulthood. He ruled the birth of gods, the cosmos, mankind and its undertakings. As warden of gates, which he opened and closed, he was depicted with a doorkeeper’s keys and staff. His two faces meant that he watched entrances as well as exits, and saw into the internal as well as the external world, left and right, above and below, before and after, for and against. His shrines were archways, such as gateways or arcades at crossing places.
He represented time, because he could see into the past with one face and into the future with the other. Hence, Janus was worshipped at the beginnings of the harvest and planting times, as well as at marriages, deaths and other beginnings. He represented the middle ground between barbarism and civilization, rural and urban space, youth and adulthood. Having jurisdiction over beginnings Janus had an intrinsic association with omens and auspices.
Whenever the symbolism of Janus relates to time, between the past (which is no longer) and the future (which is not yet), the true Face of Janus—that which looks at the present and is supposed to face us—is not shown; it is neither one nor the other of the two we can see. This third face is, in fact, invisible because the present in its temporal manifestation is but an intangible and imperceptible instant.
Sometimes Janus is shown with two keys, those of the solstice gates, Janua Celi and Janua Inferni, corresponding respectively to the winter and summer solstices, the two extremes in the sun’s annual course, for as master of time, Janus is the janitor who opens and closes this cycle. Janus is also the god of initiation into the mysteries.