Mu'awiya turned the caliphate into a family inheritance
The first four caliphs after Muhammad were chosen, not born to the office. Mu'awiya, founder of the Umayyad dynasty, broke that pattern by naming his son Yazid as successor, an unprecedented step that made the caliphate hereditary and set off opposition that outlived him, culminating in the Battle of Karbala and the Second Fitna.
He came from Mecca's leading Quraysh tribe. His father, Abu Sufyan, was a caravan merchant trading with Syria who led Meccan resistance to Muhammad, commanding at the Battle of Uhud in 625, where Mu'awiya also fought. Mu'awiya's sister Umm Habiba married Muhammad in 629, and when Muslims took Mecca in 630 the family converted. Mu'awiya, one of only seventeen literate Qurayshites, became one of Muhammad's scribes.
Under Abu Bakr he led the vanguard for his brother Yazid during the conquest of Byzantine Syria, and he rose steadily until his kinsman Uthman made him governor of the province. There he allied with the powerful Banu Kalb tribe, fortified coastal cities and launched the first Muslim naval campaigns against Byzantium. When Uthman was assassinated in 656, Mu'awiya demanded vengeance and refused to accept Ali as caliph. Their armies fought to a stalemate at Siffin in 657, arbitration failed, and after Ali was assassinated in 661, Mu'awiya pressed Ali's son Hasan to abdicate and was recognised throughout the caliphate.
He ruled from 661 until his death in 680, leaning on loyal Syrian Arab tribes and a mostly Christian bureaucracy. He is credited with creating departments for the postal route, correspondence and the chancellery, and his was the first caliph's name to appear on coins, inscriptions and documents. His troops raided Byzantine territory by land and sea almost every year, even besieging Constantinople, and in 670 the commander Uqba ibn Nafi began the conquest of central North Africa.
Opinion on him splits sharply. Sunni Muslims revere him for having been among Muhammad's companions and for writing down Quranic revelation, though critics fault him for lacking the piety of his predecessors and turning the office into a kingship. Shia tradition condemns him for opposing Ali and accuses him of poisoning Hasan.
Source: Mu'awiya I
