Mars, after Jupiter, was the most important deity in the Roman pantheon, and was worshipped throughout central and southern Italy.
His probable origin was as a vegetation god. He was the son of Jupiter and Juno; his Greek counterpart is Ares.
As a god of war his festivals were celebrated in the spring, the beginning of the war campaign season, and so his name was given to the first month of the old Roman year, and a month of violent weather, which makes it seem appropriate that it should have been dedicated to the god of war.
According to one convention it was a Roman general, before setting out on combat, would invoke Mars in his sanctuary.
The sacred spears and shields (ancilia) of Mars were kept in one of his temples in the heart of the city. At the outbreak of war, the consul had to shake these spears and shout “Mars vigila!” (Mars, wake up!) If the spears moved by themselves, this was a bad omen.
In March and October, the beginning and ending of the campaigning season, the ancilia were carried in procession by his priests. One of his special festivals involved a horserace and the sacrifice of one of the horses, whose head was cut off and decorated with cakes.
The war god is depicted in an armored suit wearing a plumed hat and bears a shield and spear. His retinue includes Metus (Fear), Demios (Dread), Phobos (Alarm), Eris (Discord), and Pallor (Terror). Mars is often linked with Bellona, the minor Roman war-goddess, who drives his chariot.
He actively participated in the primordial between the gods and the giants. His consort was Venus, and is the father of Harmonia, Cupid, and Anterios.
He is also romantically linked to vestal Iha, who was buried alive for contravening the laws of her sisterhood. Through Iha Mars fathered Romulus, the alleged founder of the city of Rome, and Remus, who was slain by Romulus.
The training ground for future Roman legionaries was known as the Campus Martius (field of Mars).
Mars favorite animals were the wolf and woodpecker. The fig tree and laurel were associated with him.
He seemed to be an agricultural god as well, as Mars was the protector of the fields not only in times of war, but also against disease and unfavorable weather. A.G.H.
Cotterell, Arthur, A Dictionary of World Mythology, New York, G. P. Putman’s Sons, 1980, p. 147
Grimal, Pierre, Larousse World Mythology, Secaucus, New Jersey, Chartwell Books, 1965, p. 179
Jordan, Michael, Encyclopedia of Gods, New York, Facts On File, Inc. 1993, p. 156