Tokhtamysh rose to power with Timur's help, then lost everything fighting him
Again and again the young fugitive Tokhtamysh fled to Timur's court after losing battles, once escaping by swimming across the Syr Darya while wounded. Timur finally installed him as khan. Tokhtamysh went on to reunite the Golden Horde and sack Moscow, then turned on his protector and was ruined.
A descendant of Genghis Khan through Jochi's thirteenth son, Tuqa-Timur, Tokhtamysh was born around 1342. His father ruled the Mangyshlak peninsula until refusing to join a campaign by his cousin and overlord Urus Khan, who had him executed. Often described as uncle and nephew, Urus and Tokhtamysh were in fact fourth cousins. The boy submitted, was forgiven for his youth, rebelled in 1373, submitted again, and in 1375 fled for good.
Reaching Timur in 1376, he gained backing, but lost to Urus' son Qutluq Buqa and then to another son, Toqtaqiya. Timur refused Urus' demand to hand him over and faced Urus down through the winter of 1376 to 1377. After Urus died, Timur declared Tokhtamysh khan. Even so, the new khan was beaten by yet another son, Tīmūr Malik, until Timur's army took Sighnaq in 1379 and the rival was killed after his own emirs betrayed him.
In 1380 Tokhtamysh moved west and became khan at Sarai. He then crossed the Volga against the warlord Mamai, weakened by his defeat by the Russians at Kulikovo, won over many of his emirs and beat him on the Kalka river. Tokhtamysh became the first khan in more than twenty years to govern both wings of the Golden Horde. He made peace with the Genoese of Crimea for steady revenue and confirmed the privileges of emirs and chiefs.
Dmitry Donskoy of Vladimir-Suzdal recognised him as overlord but held back tribute, and in 1382 Tokhtamysh besieged and sacked Moscow, restoring tribute payments. His break with Timur was the turning point: Timur invaded twice and inflicted crushing defeats that undid everything he had built. He lost the throne in 1395, died in 1406, and is often called the last great ruler of the Golden Horde.
Source: Tokhtamysh
