In the early 17th century the eastward movement of Russians was slowed by the internal problems in the country during the Time of Troubles. However, very soon the exploration and colonization of the huge territories of Siberia was resumed, led mostly by Cossacks hunting for valuable furs and ivory. While Cossacks came from the Southern Urals, another wave of Russians came by the Arctic Ocean. These were Pomors from the Russian North, who already had been making fur trade with Mangazeya in the north of the Western Siberia for quite a long time. In 1607 the settlement of Turukhansk was founded on the northern Yenisei River, near the mouth of Lower Tunguska, and in 1619 Yeniseysky ostrog was founded on the mid-Yenisei at the mouth of the Upper Tunguska.