Khalid Bin Wālid

Khalid was a horseman from the aristocratic clan of the Quraysh tribe, Makhzum, who had previously staunchly opposed Muhammad. He played an important role in defeating Muslim forces at the Battle of Uhud in 625 AD. After he converted to Islam in 627 AD or 629 AD, he was appointed commander by Muhammad, who gave him the title Saifullah ('Sword of Allah'). Khalid coordinated the safe withdrawal of Muslim troops during the failed expedition to Mu'ta against the Arab allies of Byzantium in 629 and led the Bedouin contingent of the Muslim army during the capture of Mecca and the Battle of Hunain around 630. After Muhammad's death, Khalid was appointed to suppress or subdued Arab tribes in Najd and Yamama (both regions in central Arabia) who opposed the nascent Muslim state, defeated the rebel leaders Tulaihah at the Battle of Buzakhah in 632 and Musailamah at the Battle of Aqraba in 633.

Khalid then moved against the mostly Christian Arab tribes and Sassanid Persian garrisons in the Euphrates valley in Iraq. He was reassigned by Abu Bakr to command Muslim forces in Syria and he led his men there in an unconventional movement across the long, waterless expanse of the Syrian Desert, enhancing his reputation as a military strategist. As a result of decisive victories against the Byzantines at Ajnadain (634), Fahl (634 or 635), Damascus (634-635) and Yarmuk (636), the Muslims under Khalid managed to control most of Syria. He was later removed from high command by Umar. Khalid continued his service as a key lieutenant of his successor, Abu Ubaidah ibn al-Jarrah in the sieges of Homs and Aleppo and the Battle of Qinnasrin, all in 637–638, which collectively precipitated the retreat of the Byzantine imperial forces under Emperor Heraclius of Syria. Umar dismissed Khalid from his post as governor of Qinnasrin thereafter and he died in Medina in 642.

Khalid is generally considered by historians to be one of the most capable and experienced of early Islamic generals. His achievements are widely remembered by Arab Muslims. Islamic traditions praise Khalid for his battlefield tactics and effective leadership during the early Muslim conquests, but also accuse him of illegally executing members of the Arab tribe that had converted to Islam, namely members of the Banu Jadhima during Muhammad's lifetime. and Malik bin Nuwairah during the Riddah war, as well as moral and fiscal violations in Syria. His military fame unsettled some devout early Muslims, including Umar bin Khattab, who feared it could develop into a cult of the individual.