Established by Muslim Tatars and Turks in the mid-fifteenth century. Although not completely independent of Ottoman sultans, its political and social institutions developed autonomously, blending Tatar steppe traditions with Ottoman bureaucratic and dynastic practices. Its economy was largely trade-based: slaves from the northern Slavic settlements, foodstuffs, and fine finished goods; Jews and Christians played important ecoonomic roles. Eighteenth-century Russian expansion and Crimean-Ottoman decline brought about its defeat by Russian armies between 1768 and 1774. Under Catherine II, the entire peninsula was annexed to the Russian empire.