The mourning of Muharram is a set of religious rituals observed predominantly by Shia Muslims, largely during the month of Muharram, the first month of the Islamic calendar. These annual rituals commemorate the death of Husayn ibn Ali, grandson of the Islamic prophet Muhammad and the third Shia imam. Husayn and his small retinue were slaughtered in the Battle of Karbala on 10 Muharram 61 AH against the army of the Umayyad caliph Yazid ibn Mu'awiya. The battle followed Husayn's refusal to pledge his allegiance to Yazid, who is often portrayed by Muslim historians as impious and immoral. In Shia Islam, Karbala symbolizes the eternal struggle between good and evil, the pinnacle of self-sacrifice, and the ultimate sabotage of Muhammad's prophetic mission. Historically, the event served to crystallize the Shia community into a distinct sect and remains an integral part of their religious identity to date.

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.