Yermak Timofeyevich (1532 — 06.08.1585) was a Cossack who started the Russian conquest of Siberia, in the reign of Tsar Ivan the Terrible.

The origins of Yermak are still not precisely determined: he came possibly from Don or Volga, possibly from Arkhangelsk region or the Ural mountains. He fought in the Livonian War, after which he was engaged into service of Stroganov merchants, on whose behalf he marched with some troops into Siberia. The conquest of Siberia began in 1581. Before that Siberia belonged to the Tatars. In the spring of 1583, after the first victories, Yermak sent to the Tsar Ivan the Terrible message of joining Siberia to Russia. King sent in response new troops, as well as chain armor as a gift personally to Yermak. Yermak died in 1585 in a fight with Khan Kuchum - legend says it that he jumped into the river Irtysh in the same chain armor and got drowned, not reached his boat (now the territory of the Tyumen region). The decisive battle between Cossacks and Kuchum on the Irtysh is shown on the painting of Vasily Surikov Yermak's Conquest of Siberia.

In fact, Yermak's success did not lead to the immediate accession of Western Siberia, it happened later.
Especially honored is Yermak in Western Siberia, many villages and institutions bear his name.

See also Cossacks