Introduction: New Perspectives on Religion and Warfare in the Roman Empire

Although Rome possessed an empire by the end of the third century BC, the period known as the Roman Empire technically begins when Octavian was transformed into Augustus in 27 BC by a series of senatorial decrees regularizing his constitutional position. He became the first princeps of the many who would reign over the Roman Empire, which endured for several hundred years. As rulers, the emperors believed that they required the unqualified support of the gods in order both to maintain Rome's rule (its imperium) and to wage war successfully. Rome's religious traditions in the imperial period with regard to its military forces were largely carried over from the Republic. There were, however, both minor and major shifts in emphasis, and some marked features of Rome's religious military practices in the Republic faded away, while more emphasis came to be given to others. Roman gods still received their sacrifices before battle and a share of the booty once a successful campaign was concluded, but supplications to win their favour were very much a ritual of the past, and few new temples (albeit important ones) were now built to celebrate military successes and thank the gods' role in these. Much more emphasis was placed on permanent military monuments for commemorative purposes: the tropaea (victory trophies) and the stone arches celebrating triumphs.