Siege of Herat (651)

The Siege of Herat was part of the Islamic conquest of Persia. Caliph Umar (634-644 CE) launched an offensive against the Sassanid Persian Empire in 642 and by late 651 almost all of the Sassanid empire was conquered, except Khorasan. A veteran military commander, Ahnaf ibn Qais, was appointed by the caliph for the conquest of Khurasan, which in those time comprises most of present-day north eastern Iran, Afghanistan and Turkmenistan. By 651 Ahnaf had captured Khurasan and the last Sassanid emperor Yazdegerd III was defeated in his last struggle against Caliphate at the Battle of Oxus river, whereupon he fled to Merv and eventually was murdered by a miller in 651. With him ended the last non-Muslim Iranian dynasty.