Mars fathered twin boys Remus and Romulus. It is believed that Romulus later founded Rome and that's why we consider Mars to be the father of the Roman people. He is second in importance to Jupiter and is the dominant military God. Campus Matius became a place to worship him and generally two festivals where held each year to honor him. October is an important month when talking about Mars. October ended the season of farming and began military campaigning.
As the legend goes, during the rule of King Numa Pompilius the battle shield of Mars fell from the sky into Rome. It was thought that his shield was essential to the well-being of the Roman people and their republic. It's believed that Pumpilius had 11 more shields made as replicas to dismay anyone who would try and steal the original. in total the 12 of them hung on the wall and were guarded by Roman Priests. This would signify that Mars and his efforts in war were just enough to protect.
Aside from war, Mars was first associated with agriculture, vegetation, and fertility. As Rome became more war-like so did Mars. He never lost his ties to agriculture though. In many pieces of art from that time period, he can be seen with vegetation on his spear.
