He showed interest in Sufism, a form of mysticism.

He showed interest in Sufism, a form of mysticism. Timur may have hoped to find popular leaders whom he could use for his own purposes. But he encountered ill-treated Iranians who proved that they knew him perhaps better than he knew himself. His legacy was the reverse of stability to Iran; and division of his ill-assimilated conquests among his sons ensured that an integrated Timurid Empire would never be achieved.

The Timurid state came to being an integrated Iranian empire under Timur's son, Shahrokh Shah (1405-47), who endeavored to weld Azerbaijan, which demanded three military expeditions, as well as western Persia to Khurasan (which means in Persian “land of sunshine”) and eastern Persia in order to form a united Timurid state for a short and troubled period of time. He only succeeded in loosely controlling western and southern Iran from his beautiful capital at Herat.

He made Herat the seat of a splendid culture, the atelier of great miniature painters of Herat school, Behzad notable among them, and the home of a revival of Persian poetry and philosophy. This revival was not unconnected with an effort to claim for an Iranian center once more the leadership in the propagation of Sunni ideology; Herat used to send copies of Sunni canonical works on request to Egypt.

The reaction in Shi'ism's ultimate victory under the Safavid shahs of Persia was, however, already in preparation. In the mean time, the " Qara Qoyunlu " (Black Sheep) Turkman, used to dominate Western Iran. In Azerbaijan they had replaced their former masters, the Jalayirids. Timur had put these Qara Qoyunlu to run away, but in 1406, they regained their capital, Tabriz. On Shahrokh's death, Jahan Shah (reigned c. 1438-67) extended Qara Qoyunlu rule out of the northwest deeper into Iran.

The Timurids relied on their old allies, the Qara Qoyunlus' rival Turkman of the " Aq Qoyunlu " (White Sheep) clans, whose Jahan Shah was destroyed by the Uzun Hassan of Aq Qoyunlu by the end of 1467. Uzun Hassan (1453-78) achieved a short-lived Iranian empire, but under his son Yaqub (1478-90), the state was subjected to fiscal reforms associated with a government-sponsored effort to reapply hard purist principles of orthodox Islamic rules for revenue collection.

Yaqub attempted to purge the state of taxes introduced under the Mongols and not sanctioned by the Muslim canon. His Sunni fanaticism was discredited when the inquiries made into his activities by the orthodox religious authorities.