Romans went to war with the gods on their side, or, in the case of Jupiter, literally with this god at the front - carried into battle in the vanguard of each legion in the form of his sacred eagle. Mounted on a pole, the eagle, one for each of Rome's legions, was a symbol of Jupiter and of Roman dominion wherever the legions marched. Jupiter was also the god who sent omens of victory, often a flight of living eagles. Other gods supported Rome's military endeavours: Mars had been prominent in the Republic, but from Augustus on, Mars in his guise as Mars Ultor (Mars the Avenger) becomes a divinity of considerable potency. The goddess Victory and her 'trademarks', the tropaea - assemblages of arms and armour captured from the enemy - dominate coins, reliefs and architecture: and she was the only martial deity whose iconography made a seamless transition from pagan to Christian Rome. Roman beliefs in their various war-gods were expressed through a variety of state and personal rituals, and manifested themselves in art and monumental architecture. Soldiers expressed their individual piety in inscriptions on both reliefs and altars, venerating Jupiter Optimus Maximus, the main god of victory, but also numerous other Roman gods, and their own indigenous deities if the soldiers were from places other than Italy.