Stroganov family
Besides the Novgorodians and the indigenes, Muscovites also had to contend with the various Muslim Tatar khanates to the east of Muscovy. In 1552 Ivan IV, the Tsar of All the Russias, took a significant step towards securing Russian hegemony in Siberia when he sent a large army to attack the Kazan Tartars and ended up obtaining the territory from the Volga to the Ural Mountains. At this point the phrase "ruler of Obdor, Konda, and all Siberian lands" became part of the title of the Tsar in Moscow. Even so, problems ensued after 1558 when Ivan IV sent (ca 1533–1577) to colonize land on the Kama and to subjugate and enserf the Komi living there. The Stroganov family soon came into conflict (1573) with the Khan of Sibir whose land they encroached on. Ivan told the Stroganovs to hire Cossack mercenaries to protect the new settlement from the Tatars. From ca 1581 the band of Cossacks led by Yermak Timofeyevich fought many battles that eventually culminated in a Tartar victory (1584) and the temporary end to Russian occupation in the area. In 1584 Ivan's son Fyodor sent military governors (voivodas) and soldiers to reclaim Yermak conquests and officially to annex the land held by the Khanate of Sibir. Similar skirmishes with Tartars took place across Siberia as Russian expansion continued.