Yazid I's army kills 11,000 people of Medina including notable Sahabas in Battle of al-Harrah.

The Battle of al-Harra (Arabic: , romanized: Yawm al-arra lit.'the day of al-Harra') was fought between the Syrian army of the Umayyad caliph Yazid I (r. 680683) led by Muslim ibn Uqba and the defenders of Medina from the Ansar and Muhajirun factions, who had rebelled against the caliph. The battle took place at the lava field of Harrat Waqim in the northeastern outskirts of Medina on 26 August 683 and lasted less than a day.

The elite factions of Medina disapproved of the hereditary succession of Yazid, unprecedented in Islamic history until that point, resented the caliph's impious lifestyle, and chafed under Umayyad economic acts and policies. After declaring their rebellion, they besieged the Umayyad clan resident in Medina and dug a defensive trench around the city. The expeditionary force sent by Yazid together with the local Umayyads, who had since been released from the siege, encamped at Harrat Waqim where they were confronted by the rebels. Despite an initial advantage, the Medinans were routed as a result of the defection of one of their factions, the Banu Haritha, which enabled Umayyad horsemen led by Marwan ibn al-Hakam to attack them from the rear.

Afterward, the army pillaged Medina for three days, though accounts of the plunder vary considerably. The Syrian army proceeded to besiege the rebel leader Abd Allah ibn al-Zubayr in Mecca, though Ibn Uqba died en route. In contrast to Ibn al-Zubayr's call for a shura to decide the caliphate and his success in resisting the Umayyads, the rebels in Medina lacked a political program and military experience. The Islamic traditional sources list the Battle of al-Harra and its aftermath as one of the Umayyads' 'major crimes' and malign Ibn Uqba for his role in the plunder of Medina.

Yazid ibn Mu'awiya ibn Abi Sufyan (Arabic: يزيد بن معاوية بن أبي سفيان, romanized: Yazīd ibn Muʿāwiya ibn ʾAbī Sufyān; c. 646 – 11 November 683), commonly known as Yazid I, was the second caliph of the Umayyad Caliphate. He ruled from April 680 until his death in November 683. His appointment 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.

Yazid's nomination as heir apparent in 676 CE (56 AH) by his father Mu'awiya I was opposed by several Muslim grandees from the Hejaz region, including Husayn and Abd Allah ibn al-Zubayr. The two men refused to recognize Yazid following his accession and took sanctuary in Mecca. When Husayn left for Kufa in Iraq to lead a revolt against Yazid, he was killed with his small band of supporters by Yazid's forces in the Battle of Karbala. Husayn's death caused resentment in the Hejaz, where Ibn al-Zubayr called for a consultative assembly to elect a new caliph. The people of Medina, who supported Ibn al-Zubayr, held other grievances toward the Umayyads. After failing to gain the allegiance of Ibn al-Zubayr and the people of the Hejaz through diplomacy, Yazid sent an army to suppress their rebellion. The army defeated the Medinese in the Battle of al-Harra in August 683 and the city was sacked. Afterward, Mecca was besieged for several weeks until the army withdrew as a result of Yazid's death in November 683. The Caliphate fell into a nearly decade-long civil war, ending with the establishment of the Marwanid dynasty (the Umayyad caliph Marwan I and his descendants).

Yazid continued Mu'awiya's decentralized model of governance, relying on his provincial governors and the tribal nobility. He abandoned Mu'awiya's ambitious raids against the Byzantine Empire and strengthened Syria's military defences. No new territories were conquered during his reign. Yazid is considered an illegitimate ruler and a tyrant by many Muslims due to his hereditary succession, the death of Husayn, and his attack on Medina. Modern historians take a milder view, and consider him a capable ruler, albeit less successful than his father.