The martyrdom of Husayn ibn Ali is commemorated annually by millions of Muslims on the 10th day of Moharram, which also known as Ashura.

What happened in Karbala?

Prior to his death, the Umayyad caliph Muawiyah I had nominated his son Yazid as his successor. Yazid's nomination was contested by the sons of a few prominent companions of Muhammad, including Husayn, son of the fourth caliph Ali, and Abd Allah ibn Zubayr, son of Zubayr ibn al-Awam.

The Battle of Karbala took place within the crisis environment resulting from the succession of Yazid I. Immediately after succession, Yazid instructed the governor of Medina to compel Husayn and a few other prominent figures to pledge their allegiance (Bay'ah).

Husayn, however, refrained from making such a pledge, believing that Yazid was openly going against the teachings of Islam and changing the sunnah of Muhammad. He, therefore, accompanied by his household, his sons, brothers, and the sons of Hasan left Medina to seek asylum in Mecca.

On the other hand, the people in Kufa, when informed of Muawiyah's death, sent letters urging Husayn to join them and pledging to support him against the Umayyads. Husayn wrote back to them saying that he would send his cousin Muslim ibn Aqeel to report to him on the situation and that if he found them supportive as their letters indicated, he would speedily join them because an Imam should act in accordance with the Quran and uphold justice, proclaim the truth, and dedicate himself to the cause of God. The mission of Muslim was initially successful and according to reports, 18,000 men pledged their allegiance. But the situation changed radically when Yazid appointed Ubayd Allah ibn Ziyad as the new governor of Kufa, ordering him to deal severely with Ibn Aqeel.

In Mecca, Husayn learned assassins had been sent by Yazid to kill him in the holy city in the midst of Hajj. Husayn, to preserve the sanctity of the city and specifically that of the Kaaba, abandoned his Hajj and encouraged others around him to follow him to Kufa without knowing the situation there had taken an adverse turn.

On the way, Husayn found that his messenger, Muslim ibn Aqeel, had been killed in Kufa. Husayn encountered the vanguard of the army of Ubaydullah ibn Ziyad along the route towards Kufa. Husayn addressed the Kufan army, reminding them that they had invited him to come because they were without an Imam. He told them that he intended to proceed to Kufa with their support, but if they were now opposed to his coming, he would return to where he had come from. In response, the army urged him to proceed by another route. Thus, he turned to the left and reached Karbala, where the army forced him not to go further and stop at a location that had limited access to water.

Ubaydullah ibn Ziyad, the governor instructed Umar ibn Sa'ad, the head of the Kufan army, to offer Ḥusayn and his supporters the opportunity to swear allegiance to Yazid. He also ordered Umar ibn Sa'ad to cut off Husayn and his followers from access to the water of the Euphrates. On the next morning, Umar ibn Sa'ad arranged the Kufan army in battle order.

The Battle of Karbala lasted from morning to sunset on October 10, 680 (Muharram 10, 61 AH). Husayn's small group of companions and family members (in total around 72 men and the women and children) fought against a large army under the command of Umar ibn Sa'ad and were killed near the river (Euphrates), from which they were not allowed to get water. The renowned historian Abū Rayḥān al-Bīrūnī states:

… [T]hen fire was set to their camp and the bodies were trampled by the hoofs of the horses; nobody in the history of the human kind has seen such atrocities.

Once the Umayyad troops had murdered Husayn and his male followers, they looted the tents, stripped the women of their jewelry, and took the skin upon which Zain al-Abidin was prostrate. Husayn's sister Zaynab was taken along with the enslaved women to the caliph in Damascus when she was imprisoned and after a year eventually was allowed to return to Medina. (ILKHA)