In the late 7th and early 8th centuries CE, the Islamic Umayyad Caliphate, established after the death of Muhammad, underwent a period of rapid growth. In 647 CE, 40,000 Arabs forced the Byzantine governor of northern Africa to submit and pay tribute, but failed to permanently occupy the region. After an interlude, during which the Muslims fought a civil war, the invasions resumed in 665, seizing Byzantine North Africa up to Bugia over the course of a series of campaigns, lasting until 689. A Byzantine counterattack largely expelled the Arabs but left the region vulnerable. Intermittent war over the inland provinces of North Africa continued for the next two decades. Further civil war delayed the continuation of further conquest, but an Arab assault took Carthage and held it against a Byzantine counterattack.