Mars was the son of Jupiter and Juno, the king and queen of all the gods. Mars was tall and handsome, and mean and self-centered. Mars was the god of war.
In Roman mythology, Mars did not care who won or lost a battle. He just liked to see bloodshed. Most of the other gods stayed as far away from Mars as possible. But Mars was very popular in the mortal world. Men, especially men in the military, prayed that Mars would fight on their side.