Abul-Qasim Babur Mirza, the Timurid ruler in Khurasan, had in 1454 invaded Transoxiana, then under the control of Abu Sa'id Mirza, in retaliation for the latter's seizure of Balkh.

He had quickly laid siege to Samarkand.

The conflict between the two soon ended, however, with the Oxus River agreed to as the border.

This has remained in effect until Babur's death in 1457.

Babur's son Mirza Shah Mahmud succeeds him but, as he is still a boy, his hold on power is weak.

Weeks after Babur's death, Ibrahim Mirza bin Ala-ud-Daulah overthrows Shah Mahmud and therefore becomes the ruler of Khurasan.

However, Abu Sa'id Mirza, invades in July 1457 and occupies Balkh but is unable to conquer Herat.

Ibrahim's troubles increase when Jahan Shah of the Black Sheep Turkmen invades as well.

After occupying Gurgan, he defeats Ibrahim outside Astarabad.

Ibrahim's father Ala-ud-Daulah Mirza bin Baysonqor meets up with him in Herat to offer assistance, but in the end they both flee from the region.

Jahan Shah, recognizing the weakness of Timurid authority in Herat, invades on June 28, 1458, and takes the city.

He is unable to keep it, however, due to pressures from within his principality of Kara Koyunlu plus the increasing threat from Uzun Hasan of Aq Qoyunlu.

Obliged to negotiate the borders of his state with Abu Sa'id Mirza, he decides after negotiations to return territorial demarcations to what they had been during the reign of Shahrukh Mirza.

Thus, Khurasan, Mazandaran and Gurgan are returned to the Timurids and Abu Sa'id Mirza returns and takes Herat a second time on December 22, 1458.

While leaving the territory, however, the Turkmens had ravaged Khurasan, and when Abu Sa'id Mirza arrives to take Herat, he finds its residents frightened.

In order to ease their fears, he sends the major portion of his army back towards Bukhara.

His rival claimants to Samarkand—namely, Ala-ud-Daulah Mirza bin Baysonqor, his son Ibrahim Mirza bin Ala-ud-Daulah and Sultan Sanjar Mirza—seeing his position thus weakened, decide to form an alliance and take this opportunity to destroy Abu Sa'id once and for all.

Abu Sa'id Mirza, on receiving intelligence of his rivals’ advance, sets out to meet this threat head on despite being numerically outnumbered, and sends for reinforcements.

The vanguard of Ala-ud-Daulah Mirza bin Baysonqor, Ibrahim Mirza bin Ala-ud-Daulah and Sultan Sanjar Mirza appears between Marv and Sarakhs in March 1459.

Battle lines are drawn and a pitched battle ensues.

Reinforcements arrive for Abu Sa'id Mirza at the right time under Amir Ali Farsi and Amir Syed Asil, and with their help he defeats his enemies.

Amir Ali Farsi and Amir Syed Asil are sent in pursuit of Ala-ud-Daulah Mirza bin Baysonqor and Ibrahim Mirza bin Ala-ud-Daulah, who had fled to Mazniyan; Sultan Sanjar Mirza is captured and is executed.

Ibrahim dies only a few months later; his father will die the following year.

Abu Sa'id has conquered eastern Iran and most of Afghanistan by 1461, agreeing with Jahan Shah to divide Iran between them.