Intent on conquering Herat, Ahmad Shah besieged the city for a long period of time until it finally fell in late 1750.

[1][2][3] With the fall of Herat, Ahmad Shah continued his campaign into Khorasan, invading the Afsharids and besieging Mashhad, where he remained until November 1750.

He besieged the city and demanded its surrender, which the governor, Jafar Khan, refused despite only having a few thousand men as garrison.

His nephew, Abbas Quli, took command of the garrison and repulsed the Afghan forces, inflicting horrific casualties unto them, including some 12,000 dead, and thousands more wounded.

The harsh winter weather killed thousands while the Afghans retreated,[1] and Ahmad Shah was forced to leave behind much of his baggage, including his artillery and food supplies.