Janus is the Roman god of doorways, beginnings and endings.
Janus received the gift to see both future and past from Cronus in reward for the hospitality he received. This is why he is most often depicted as having two faces or heads, facing in opposite directions - similar heads of gods related to Hermes have been found in Greece, perhaps suggesting a compound god. These double-headed figures have precursors in Assyrian depictions of Oannes with a human head in front and a fish head behind.
- ↑ (Hamilton 1998, p. 44)