Battle of Karbala

Mu'awiya broke with precedent by having his son Yazid acknowledged as heir, which many regarded as a breach of his treaty with Hasan. When Mu'awiya died in April 680, Husayn — Hasan’s younger brother and, since Hasan’s death, head of Muhammad’s clan of Hashim — refused to swear allegiance and left Medina for Mecca. Letters from Ali’s partisans in Kufa invited him to lead them against Yazid. His cousin Muslim ibn Aqil, sent ahead, found wide support, but the new governor, Ubayd Allah ibn Ziyad, broke the movement and had him executed. Unaware of this, Husayn set out from Mecca on 9 September 680 with his family and a small band of followers.

Near al-Qadisiyya the caravan was intercepted by about 1,000 men under al-Hurr, and on 2 October Husayn was forced to camp on the desert plain of Karbala, about 70 km north of Kufa. An army of 4,000 under Umar ibn Sa'd arrived and cut the camp off from the Euphrates, and negotiations failed when Ibn Ziyad demanded submission. On the morning of 10 October Husayn’s men — by most accounts 32 horsemen and 40 foot soldiers — fought until almost all were dead; Husayn himself, wounded many times, was killed and beheaded. About seventy of his people fell, among them some twenty descendants of Abu Talib, including sons of Husayn and of Hasan. The women and Husayn’s surviving son Ali, too ill to fight, were taken with the heads of the dead to Kufa and then to Yazid in Damascus.

Karbala fed the revolts of the Second Fitna — the “penitents” (tawwabun) of Kufa and the uprising of al-Mukhtar, who killed several of the men held responsible. Above all it gave the Alid cause a religious identity of its own: its anniversary, Ashura, is marked by mourning rites, processions — recorded in Baghdad as early as 963 — and, in Iran, the taziya passion plays, and the Arba'in pilgrimage to Husayn’s shrine at Karbala draws millions. The battle played a decisive role in the development and consolidation of what became Shia Islam. The detailed narrative goes back to the Kufan historian Abu Mikhnaf (d. 773/775), whose account survives through al-Tabari and al-Baladhuri; the Syriac history of Theophilus of Edessa confirms that Husayn and most of his men died at Karbala.