Short answers, pulled from the story.
The Khanate of Sibir was a Siberian Tatar state in western Siberia that functioned as an independent polity from the 15th century until 1598. It was founded following the break-up of the Golden Horde and was ruled by competing members of the Taibugid and Shaybanid dynasties.
The Khanate of Sibir was the northernmost Muslim state in recorded history. Its northern territories reached the lower Ob River, and its ruling khan and noble mirzas professed Islam while much of the general population practiced shamanism or mixed beliefs.
Both dynasties were patrilineal descendants of Genghis Khan through his son Jochi and Jochi's fifth son Shayban, who died in 1266. The Taibugids traced their line through Taibuga, the khanate's founder, while the Shaybanids claimed direct Genghisid descent. Neither line could permanently dislodge the other, and control alternated between them throughout the khanate's history.
Cossack leader Yermak Timofeyevich defeated Khan Kuchum's forces at the Battle of Chuvash Cape in 1582, then entered the capital Iskar that same year. Kuchum killed Yermak in 1584 and temporarily regained control, but Russian forces continued advancing and in 1598 defeated Kuchum on the banks of the Ob River, ending his rule.
The khanate had an ethnically diverse population that included Siberian Tatars and several Uralic peoples: the Khanty, the Mansi, and the Selkup. The ruling class was predominantly Turkic and Muslim, while many ordinary inhabitants practiced shamanism or traditional beliefs.
The original capital was Chimgi-Tura, founded by the first khan Taibuga. After the Taibugid Muhammad killed the Shaybanid Ibak around 1495, he moved the capital to Iskar on the Irtysh River, also known as Sibir or Qashliq. That site remained the capital until Yermak's Cossacks entered it in 1582.