This article considers the relationship between Christians and Muslims in Caucasia in the eleventh to fourteenth centuries, with special reference to the King- dom of Georgia, the most powerful non-Muslim state in the region. Georgia already had a Muslim population of its own-Tbilisi was a Muslim city up to the twelfth century-but with the invasion of Turks and Mongols, Muslim culture and institutions came to exert a profound influence on the Christian king- dom, a phenomenon examined in the first part of this paper. Conversely, however, interest in Georgian culture on the part of Georgia’s Muslim inhabitants and vassals was more limited, although not entirely absent. The essay concludes by studying conversion in Caucasia, both Christian conversions to Islam and vice versa, arguing that on both sides, changes of religion among the élite were generally prompted by political necessity, such as the desire to conclude advantageous marriage alliances. ‬