the Stroganovs permission to expand into the territory along the Tobol and Irtysh Rivers which belonged to the Muslim leader Kuchum Khan. The Stroganovs proceeded to launch expeditions eastward into non-Russian territories. They pushed into the khanate of Sibir, the sister state of the former khanate of Kazan, because it maintained control over Siberia's fur in the west. During the time of the Russian conquest of Kazan in the 1540s and 1550s, Sibir had been undergoing conflicts of its own with rival clans. The khanate was on the precarious ground until the rise of Kuchum Khan, a descendant of the famed Chingis Khan, in the 1560s. Kuchum Khan built up allies among his neighbors and the Crimean Tatars in order to thwart the Stroganovs’ expansion across the Urals. In July 1572, Kuchum launched his first raid on Stroganov settlements, which resulted in almost one hundred deaths. In 1573, the Tatar army expanded and changed leadership. Kuchum's nephew, Mahmet-kul, assumed control of the Tatar army. The Stroganovs realized that they could no longer expect their settlers to remain in the lands around Perm if they only fought a defensive battle. The tsar granted the Stroganov family permission to invade Asia. However, the tsar soon changed his mind and told the Stroganovs to retract from Siberia, fearing that Russia did not have the resources or manpower to topple Kuchum Khan's empire. The Stroganovs decided to ignore the tsar's orders and, in the late 1570s, Anika Stroganov's grandsons Nikita and Maksim recruited Cossack fighters to wage war on their behalf. They elected the Cossack chieftain Yermak Timofeyevich as the leader of the Cossack brigades. According to the Stroganov Chronicle, on April 6, 1579, after hearing of Yermak's and his comrades’ “daring and bravery,” the Stroganovs sent a letter to the men asking them to come to their ancestral estates in Chusovaya and summoning them to fight against the Tatars in the name of the tsar. Since Yermak had been the most illustrious of the recruits, he became the captain (ataman) of the “conquest of Siberia.” However, there remains the question as to whether Yermak, in fact, decided to fight the war of his own accord without being pursued by the Stroganovs. This question arose due to the discrepancy between the narratives of the Stroganov Chronicle and a different Siberian chronicle, the Yespiov Chronicle. The Stroganov Chronicle portrays the family as the motivating force