Husayn ibn Ali, a grandson of Muhammad, was killed at the Battle of Karbala (depicted) by the forces of Yazid I, whom Husayn had refused to recognize as caliph.

Husayn ibn Ali was the second son of Ali and Fatima, a younger brother of Hasan and grandson of the Islamic prophet Muhammad. He is the third Shia Imam, succeeding his brother Hasan and preceding his son Ali al-Sajjad. Husayn is a prominent member of the Ahl al-Bayt and Ahl al-Kisa, and a participant in the Event of the mubahala. Muhammad described Husayn and Hasan as the leaders of the youth of paradise. After the assassination of Ali, Husayn obeyed his brother in recognizing the Hasan–Mu'awiya peace treaty. Under the treaty, Hasan ceded the caliphate to Mu'awiya on the condition that the latter should rule in compliance with the Quran and the Sunnah, a council should appoint his successor, and Hasan's supporters would receive amnesty. During the nine-year period of Hasan's abdication, Hasan and Husayn withdrew to Medina, seeking to remain removed from political involvement. After Hasan's death, the people of Kufa turned to Husayn and called for an uprising. Husayn instructed them to wait as long as Mu'awiya remained alive, in accordance with Hasan's peace treaty.