The Arab–Byzantine wars were a series of wars between the mostly Arab Muslims andthe Byzantine Empire between the 7th and 11th centuries AD, started during theinitial Muslim conquests under the expansionist Rashidun and Umayyad caliphs in the 7thcentury and continued by their successors until the mid-11th century. • The emergence of Muslim Arabs from Arabia in the 630s resulted in the rapid loss ofByzantium's southern provinces (Syria and Egypt) to the Arab Caliphate. Over the nextfifty years, under the Umayyad caliphs, the Arabs would launch repeated raids into still-Byzantine Asia Minor, twice besiege the Byzantine capital of Constantinople, and conquerthe Byzantine Exarchate of Africa. The situation did not stabilize until after the failure ofthe Second Arab Siege of Constantinople in 718, when the Taurus Mountains on theeastern rim of Asia Minor became established as the mutual, heavily fortified and largelydepopulated frontier