Yermak Timofeyevich (Ерма́к Тимофе́евич; born between 1532 and 1542 – August 5 or 6, 1585) was a Cossack ataman and is today a hero in Russian folklore and myths. During the reign of Tsar Ivan the Terrible, Yermak started the Russian conquest of Siberia. Russians' fur-trade interests fueled their desire to expand east into Siberia. The Tatar Khanate of Kazan was established by Ulugh Muhammad as the best entryway into Siberia. In 1552, Ivan the Terrible's modernized army toppled the khanate. After the takeover of Kazan, the tsar looked to the powerful and affluent Stroganov merchant family to spearhead the eastward expansion. In the late 1570s, the Stroganovs recruited Cossack fighters to invade Asia on behalf of the tsar. These Cossacks elected Yermak as the leader of their armed forces, and in 1582 Yermak set out with an army of 840 to attack the Khanate of Sibir. On October 26, 1582, Yermak and his soldiers overthrew Kuchum Khan's Tatar empire at Qashliq in a battle that marked the "conquest of Siberia". Yermak remained in Siberia and continued his struggle against the Tatars until 1584, when a raid organized by Kuchum Khan ambushed and killed him and his party. The specifics of Yermak's life, such as his appearance, background, and dates of events, remain points of controversy for historians because the texts that document his life are not reliable. However, his life and conquests had a profound influence on Siberian relations, sparking Russian interest in the region and establishing the Tsardom of Russia as an imperial power east of the Urals. There is less information about Yermak than most other notable explorers and historical figures. Much of what we know about Yermak is derived from folklore and legend. There are no contemporary descriptions of Yermak and all portraits are merely estimations. One of the Siberian chronicles, the Remezov Chronicle, written more than one hundred years after Yermak's death describes him as “flat-faced, black of beard with curly hair, of medium stature and thick-set and broad-shouldered,” but even this detailed account is not reliable because the narrator had never seen Yermak.