Janus was the Roman god of beginnings, transitions, and doorways, traditionally depicted with two faces.
His two faces symbolized looking backward and forward, making him a fitting guardian of change, passages, gates, and new beginnings. Romans invoked him when starting journeys, entering agreements, opening ceremonies, or moving from one stage of life to another. Unlike many major Roman gods, Janus had no straightforward Greek equivalent and was regarded as distinctly Roman.
The month of January, Latin Ianuarius, was named for Janus. Its position at the start of the year reflects his connection with thresholds and transitions. Janus was also associated with time, movement, boundaries, bridges, and the opening and closing of doors.
His double-faced image does not mean he was simply deceitful, as the modern adjective “Janus-faced” can suggest. In Roman religion, the two faces primarily represented awareness of what had passed and what was beginning. A temple traditionally associated with him had doors said to stand open during war and closed during peace.