A later Persian Empire re-emerged in 226 A.D. and outlived the Western Roman Empire. After a devastating war with the Byzantine Empire that left both sides severely drained, Islam came on the scene from Saudi Arabia and completely conquered the Persian Empire in a quick campaign that ended in 651 A.D. | A later Persian Empire re-emerged in 226 A.D. and outlived the Western Roman Empire. After a devastating war with the Byzantine Empire that left both sides severely drained, Islam came on the scene from Saudi Arabia and completely conquered the Persian Empire in a quick campaign that ended in 651 A.D. |