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

Husayn ibn Ali was a social, political and religious leader in early medieval Arabia. The grandson of the Islamic prophet Muhammad and an Alid, as well as a younger brother of Hasan ibn Ali, Husayn is regarded as the third Imam in Shia Islam after his brother, Hasan, and before his son, Ali al-Sajjad. Husayn is a prominent member of the Ahl al-Bayt and is also considered to be a member of the Ahl al-Kisa and a participant in the event of the mubahala. Muhammad described him and his brother, Hasan, as the leaders of the youth of paradise.

Muhammad was an Arab religious, military and political leader and the founder of Islam. According to Islam, he was a prophet who was divinely inspired to preach and confirm the monotheistic teachings of Adam, Noah, Abraham, Moses, Jesus, and other prophets. He is believed by Muslims to be the Seal of the Prophets, and along with the Quran, his teachings and normative examples form the basis for Islamic religious belief.

The Battle of Karbala was fought on 10 October 680 between the army of the second Umayyad caliph Yazid I and a small army led by Husayn ibn Ali, the grandson of the Islamic prophet Muhammad, at Karbala, Sawad.

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.