Jesus was being symbolically victorious over the rival religion of
Mithras (http://www.1911encyclopedia.org/Mithras):
QuoteMITHRAS, a Persian god of light, whose worship, the latest one of importance to be brought from the Orient to Rome, spread throughout the empire and became the greatest antagonist of Christianity.
QuoteThe second group represents, first, the birth of Mithras; then the god nude, cutting fruit and leaves from a fig-tree in which is the bust of a deity, and before which one of the winds is blowing upon Mithras;