Siberia's last khan lost his capital to Cossacks in 1582 and his family to Moscow in 1598; his descendants served the tsars as Princes Sibirsky

Kuchum, a Shaybanid descendant of Genghis Khan, took the throne of the khanate of Sibir in 1563 from Yadegar, a vassal of Moscow. In October 1582 the Cossack Yermak captured his capital, Qashliq. Kuchum killed Yermak in 1584 and fought on from the steppe with a guard of Nogai and Bukharan troops, raiding the Tatars who paid tribute to Russia. In 1591 the Russians captured two of his wives and his son Abdul-Khair. Moscow offered him terms like those given his nephew Mametkul, who received estates and noble rank. Kuchum, about 80 and almost blind and deaf, refused. On 4 August 1598 the Tara commander Andrei Voeykov set out with about 700 men. At dawn on 20 August he attacked Kuchum's camp on the Ob at the mouth of the Irmen. Kuchum's brother, a son and two adult grandsons were killed. Kuchum escaped downriver by boat with 30 men and died among the Nogai. His wives and younger children were sent to Moscow, received by Boris Godunov in January 1599, and given estates near Yaroslavl. Their descendants were titled tsarevichs of Siberia. In 1718 Peter I stripped the title after one sided with his son Alexei. A 2018 report names Igor Sibirsky, born 1966, a nuclear safety specialist, as the last of the line.