In ancient Roman religion and mythology, Mars (Latin: Mārs, pronounced [maːrs])[4] is the god of war and also an agricultural guardian, a combination characteristic of early Rome.

[9] Unlike Ares, who was viewed primarily as a destructive and destabilizing force, Mars represented military power as a way to secure peace, and was a father (pater) of the Roman people.

He may be presenting a literary myth of his own invention, or an otherwise unknown archaic Italic tradition; either way, in choosing to include the story, he emphasizes that Mars was connected to plant life and was not alienated from female nurture.

In Greek myth, the adultery of Ares and Aphrodite had been exposed to ridicule when her husband Hephaestus (whose Roman equivalent was Vulcan) caught them in the act by means of a magical snare.

[30] Scenes of Venus and Mars in Roman art often ignore the adulterous implications of their union, and take pleasure in the good-looking couple attended by Cupid or multiple Loves (amores).

Some scenes may imply marriage,[31] and the relationship was romanticized in funerary or domestic art in which husbands and wives had themselves portrayed as the passionate divine couple.

[33] In ancient Roman and Renaissance art, Mars is often shown disarmed and relaxed, or even sleeping, but the extramarital nature of their affair can also suggest that this peace is impermanent.

[36] The priesthood of the Arval Brothers called on Mars to drive off "rust" (lues), with its double meaning of wheat fungus and the red oxides that affect metal, a threat to both iron farm implements and weaponry.

[38] In his book on farming, Cato invokes Mars Silvanus for a ritual to be carried out in silva, in the woods, an uncultivated place that if not held within bounds can threaten to overtake the fields needed for crops.

[39] Mars's character as an agricultural god may derive solely from his role as a defender and protector,[40] or may be inseparable from his warrior nature,[41] as the leaping of his armed priests the Salii was meant to quicken the growth of crops.

[43] Plutarch notes that the woodpecker (picus) is sacred to Mars because "it is a courageous and spirited bird and has a beak so strong that it can overturn oaks by pecking them until it has reached the inmost part of the tree.

"[44] As the beak of the picus Martius contained the god's power to ward off harm, it was carried as a magic charm to prevent bee stings and leech bites.

[45] The bird of Mars also guarded a woodland herb (paeonia) used for treatment of the digestive or female reproductive systems; those who sought to harvest it were advised to do so by night, lest the woodpecker jab out their eyes.

[51] The Umbrian cognate peiqu also means "woodpecker", and the Italic Picenes were supposed to have derived their name from the picus who served as their guide animal during a ritual migration (ver sacrum) undertaken as a rite of Mars.

[52] In the territory of the Aequi, another Italic people, Mars had an oracle of great antiquity where the prophecies were supposed to be spoken by a woodpecker perched on a wooden column.

[53] Mars's association with the wolf is familiar from what may be the most famous of Roman myths, the story of how a she-wolf (lupa) suckled his infant sons when they were exposed by order of King Amulius, who feared them because he had usurped the throne from their grandfather, Numitor.

[57] In Roman Gaul, the goose was associated with the Celtic forms of Mars, and archaeologists have found geese buried alongside warriors in graves.

[71] Soldiers sometimes assembled at the temple before heading off to war, and it was the point of departure for a major parade of Roman cavalry held annually on July 15.

[73] The Campus Martius continued to provide venues for equestrian events such as chariot racing during the Imperial period, but under the first emperor Augustus it underwent a major program of urban renewal, marked by monumental architecture.

The Altar of Augustan Peace (Ara Pacis Augustae) was located there, as was the Obelisk of Montecitorio, imported from Egypt to form the pointer (gnomon) of the Solarium Augusti, a giant sundial.

[79] On the Altar of Peace (Ara Pacis), built in the last years of the 1st century BCE, Mars is a mature man with a "handsome, classicizing" face, and a short curly beard and moustache.

[80] Particularly in works of art influenced by the Greek tradition, Mars may be portrayed in a manner that resembles Ares, youthful, beardless, and often nude.

[88] The festivals of Mars cluster in his namesake month of March (Latin: Martius), with a few observances in October, the beginning and end of the season for military campaigning and agriculture.

The tenth bull violated ritual protocol by attempting to break free, and when killed and examined, produced ill omens, among the many that were read at the end of Julian's reign.

[110] Mars Pater is among the several gods invoked in the ritual of devotio, by means of which a general sacrificed himself and the lives of the enemy to secure a Roman victory.

[122][125] Some rituals previously conducted within the cult of Capitoline Jupiter were transferred to the new temple,[126] which became the point of departure for magistrates as they left for military campaigns abroad.

An inscription in the Alps records the gratitude of a slave who dedicated a statue to Mars Augustus as conservator corporis sui, the preserver of his own body, said to have been vowed ex iussu numinis ipsius, "by the order of the numen himself".

[137] Mars Augustus appears in inscriptions at sites throughout the Empire, such as Hispania Baetica, Saguntum,[138] and Emerita (Lusitania) in Roman Spain;[139] Leptis Magna (with a date of 6–7 AD) in present-day Libya;[140] and Sarmizegetusa in the province of Dacia.

[141] In addition to his cult titles at Rome, Mars appears in a large number of inscriptions in the provinces of the Roman Empire, and more rarely in literary texts, identified with a local deity by means of an epithet.

[142] The inscriptions indicate that Mars's ability to dispel the enemy on the battlefield was transferred to the sick person's struggle against illness; healing is expressed in terms of warding off and rescue.