quality:corruption
Rise to power

Urus was succeeded as khan by his son Toqtaqiya, who died after two months, and then by his other son, Tīmūr Malik. As before, Tokhtamysh had little luck fighting against a son of Urus, and he was easily defeated by Tīmūr Malik. Tokhtamysh fled to Timur's court once again. Hearing that Tīmūr Malik spends his time in drinking and pleasures and ignores affairs of importance, and that the exasperated people desire Tokhtamysh to rule them, Timur sent his forces to Sawran and Otrar, which surrendered. Advancing on Sighnaq, they defeated the enemy at Qara-Tal, and captured and executed Tīmūr Malik, betrayed by his own emirs, in 1379. Tokhtamysh was now installed as khan in Sighnaq, and he spent the rest of the year establishing his authority and harnessing his resources for his next target, Sarai.

In 1380, Tokhtamysh advanced westward, intent on taking over Sarai and the central and western portions of the Golden Horde. His military power intimidated his former host Qāghān Beg in the Ulus of Shiban and Qāghān Beg's cousin, the reigning khan ʿArab Shāh, who both submitted to Tokhtamysh. Now khan at Sarai, he crossed the Volga to eliminate the powerful beglerbeg Mamai, master of the westernmost portions of the Golden Horde. Weakened by his defeat at the hands of the Russians at the Battle of Kulikovo earlier that year, and by the death of his puppet khan Tūlāk, Mamai was defeated by Tokhtamysh on the Kalka river in the autumn of 1381, after Tokhtamysh had enticed away a number of Mamai's emirs. Mamai fled to the Crimea, but was eventually eliminated by Tokhtamysh's agents, who had followed in pursuit, in late 1380 or early 1381.

From a fugitive, Tokhtamysh had become a powerful monarch, the first khan in over two decades to rule both halves (wings) of the Golden Horde. In the space of a little over a year, he had made himself master of the left (eastern) wing, the former Ulus of Orda (called White Horde in some Persian sources and Blue Horde in Turkic ones), and then also master of the right (western) wing, the Ulus of Batu (called Blue Horde in some Persian sources and White Horde in Turkic ones). This promised to restore the greatness of the Golden Horde after a long period of division and internecine conflict. Tokhtamysh proceeded to solidify his authority with wisdom and restraint. Already in early 1381, he restored peace with the Genoese of the Crimea, ensuring himself a steady income. He similarly sought the cooperation of the emirs and tribal chieftains by confirming the privileges that had been conferred to them in the past.