Yazid I (20 July 647-11 November 683) was Caliph from 680 to 683, succeeding Muawiyah I and preceding Muawiyah II.
Biograpy
Yazid was the son of Muawiyah I, and he became caliph in 680 after the death of his father. Hussein ibn Ali refused to give his allegiance to Yazid when he became caliph, so Yazid accused him of treason, leading to a rebellion by Hussein and the Banu Hashim. At the Battle of Karbala on 10 October 680, Hussein and his 72 followers were massacred and beheaded, and this led to a permanent split between Sunni and Shia Islam. He died in 683 after falling from his horse.