The Khanate of Sibir as an independent polity was established in the fifteenth century, at a time when the Mongols of the house of Jochi were generally in a state of decline.

Ibak Khan, a member of a junior branch of the Shaybanid house, killed Mar and seized Chimgi-Tura.

A Taibugid restoration occurred when Mar's grandson Muhammad fled to the eastern territories around the Irtysh and killed Ibak in battle in c. 1493.

Muhammad decided not to remain at Chimgi-Tura, but chose a new capital named Iskar (or Sibir) located on the Irtysh.

The Russian conquest of Kazan in 1552 prompted the Taibugid Khan of Sibir, Yadigar, to seek friendly relations with Moscow.

[6] His decision to conduct a raid on the Stroganov trading posts resulted in an expedition led by the Cossack Yermak against the Khanate of Sibir.

Kuchum's forces were defeated by Yermak at the Battle of Chuvash Cape in 1582 and the Cossacks entered Iskar later that year.

Kuchum reorganized his forces, killed Yermak in battle in 1584, and reasserted his authority over Sibir.Over the next fourteen years, however, the Russians slowly conquered the Khanate.

In 1598 Kuchum was defeated on the banks of the Ob and was forced to flee to the territories of the Nogai, bringing an end to his rule.

Grousset says that they were 'the issue of Taibugha-bäki' without explanation ('bäki' (bek) was a princely suffix and Taibuqa was a Naiman chief at the time of Genghis Khan.)

The Stroganov chronicle says that On was killed by a chief called Chingi who spared Taibuga, sent him to fight the Ostyaks and granted him his own principality.

Another source makes On a Nogai whose 'Hoflager' (German for 'court-camp') was Kasyl-Tura at the mouth of the Ishim River about 160 kilometres (100 mi) east of Tobolsk.

When he led his followers south for better things the remaining Shaybanids gathered around Ibak Khan, who was from a junior branch of the house.