Yazid I, Muslim caliph (born 647)

Yazid ibn Mu'awiya ibn Abi Sufyan, commonly known as Yazid I, was the second caliph of the Umayyad Caliphate, ruling from April 680 until his death in November 683. His appointment by his father Mu'awiya I was the first hereditary succession to the caliphate in Islamic history. His caliphate was marked by the death of Muhammad's grandson Husayn ibn Ali and the start of the crisis known as the Second Fitna.

A caliphate is an institution or public office under the leadership of an Islamic steward with the title of caliph, a person considered a political–religious successor to the Islamic prophet Muhammad and a leader of the entire Muslim world (ummah). Historically, the caliphates were polities based on Islam which developed into multi-ethnic trans-national empires.