Formed from Golden Horde territory conquered after the Mongol invasion the Crimean Khanate was one of the strongest powers in Eastern Europe until the 18th century; in 1571 it even captured and devastated Moscow. The borderlands suffered annual Tatar invasions. From the beginning of the 16th century until the end of the 17th century, Crimean Tatar slave raiding bands exported about two million slaves from Russia and Ukraine. According to Orest Subtelny, "from 1450 to 1586, eighty-six Tatar raids were recorded, and from 1600 to 1647, seventy." In 1688, Tatars captured a record number of 60,000 Ukrainians. The Tatar raids took a heavy toll, discouraging settlement in more southerly regions where the soil was better and the growing season was longer. The last remnant of the Crimean Khanate was finally conquered by the Russian Empire in 1783.