In Europe, the fashion for heavily armored Roman cavalry seems to have been a response to the Eastern campaigns of the Parthians and Sassanids in the region referred to as Asia Minor, as well as numerous defeats at the hands of Iranian cataphracts across the steppes of Eurasia, most notably in the Battle of Carrhae in upper Mesopotamia (53 BC). Traditionally, Roman cavalry was neither heavily-armored nor decisive in effect; the Roman equites corps comprised mainly lightly-armored horsemen bearing spears and swords and using light-cavalry tactics to skirmish before and during battles, and then to pursue retreating enemies after a victory. The adoption of cataphract-like cavalry formations took hold among the late Roman army during the late 3rd and 4th centuries. The Emperor Gallienus Augustus () and his general and putative usurper Aureolus (died 268) arguably contributed much to the institution of Roman cataphract contingents in the Late Roman army.