Artabanus marched a second time against Ardashir I in 224. Their armies clashed at Hormizdegan, where Artabanus IV was killed. Ardashir was crowned in 226 at Ctesiphon as the sole ruler of Persia, bringing the 400-year-old Parthian Empire to an end, and starting the virtually equally long rule of the Sassanian Empire, over an even larger territory, once again making Persia a leading power in the known world, only this time along with its arch-rival and successor to Persia's earlier opponents (the Roman Republic and the Roman Empire); the Byzantine Empire.