Janus was the Roman god of beginnings, gates, and doorways. He was associated with the start of day and the first month of the year, called January after him. The Romans mentioned Janus first when including a list of gods in their prayers, and they named the Janiculum, one of the seven hills of Rome, in his honor.
Like a doorway that can be entered from two directions, Janus was usually pictured with two faces, one looking forward and one looking back. The temple to Janus in the Roman Forum had two sets of doors facing east and west. These doors were open during a war and closed in periods of peace.
Janus appears in one myth as the defender of an important Roman gateway When the city was under attack by a tribe known as the Sabines, Janus flooded the gate with a hot spring to prevent the invaders from entering the city. In another story, Janus used his two faces while pursuing a lover. The goddess Cardea was known for leading her admirers to a cave and then running away. When Janus accompanied her to the cave, he saw with the face in the back of his head that she was turning to leave and caught hold of her before she could escape.