The Kurt dynasty, also known as the Kartids, is a Sunni Muslim dynasty of Tajik origin, that has ruled over a large part of Khorasan during the thirteenth and fourteenth centuries.
Ruling from their capital at Herat and central Khorasan in the Bamyan, they were at first subordinates of Sultan Abul-Fateh Ghiyāṣ-ud-din Muhammad bin Sām, Sultan of the Ghurid Empire, to whom they were related, and then as vassal princes within the Mongol Empire.
Upon the fragmentation of the Ilkhanate in 1335, Mu'izz-uddin Husayn ibn Ghiyath-uddin had worked to expand his principality.
Upon Mu'izz-uddin Husayn's death in 1370, his son Ghiyas-uddin Pir 'Ali had inherited most of the Kurt lands, except for Sarakhs and a portion of Quhistan.
Timur had invited Ghiyas-uddin Pir 'Ali to a council, so that the latter could submit to him, but after the Kurt attempted to excuse himself from coming by claiming he had to deal with the Shia population in Nishapur, Timur had decided to invade.
He is encouraged by many Khurasanis, included Mu'izzu'd-Din's former vizier Mu'in al-Din Jami, who had sent a letter inviting Timur to intervene in Khurasan, and the influential shaikhs of Jam, who had persuaded many of the Kurt dignitaries to welcome Timur as the latter neared Herat.
Timur in April 1381 arrives before the city, whose citizens are already demoralized and also aware of Timur's offer not to kill anyone that does not take part in the battle.
The city falls, its fortifications are dismantled, theologians and scholars are deported to Timur's homeland, a high tribute is imposed, and Ghiyas-uddin Pir 'Ali and his son are carried off to Samarkand.