In later times Avars and Slavs still raided the remaining Byzantine lands as Maurice was hard pressed to defend his native Cappadocia and Armenia from the mighty Sassanians of Persia. By 592 the Byzantine ruler, once he defeated the Persian menace, was bent on revenge and counterattacked in full force, soon reverting the roles (see Maurice's Balkan campaigns). Repeated, massive defeats shook the Avaro-Slavic hordes as strong organized Byzantine armies penetrated north of the Danube into Wallachia, and eventually, under general Priscus, crushed the enemy along the river Tisza in the very heart of Pannonia. It was Phocas' rebellion against Maurice in 602 that ultimately saved the Avars. In the same year Khagan Bayan died, his empire now safe and firmly established.