Erzurum and its environs have been one of the settlement centers of human beings since the prehistoric age and have become strategically very important in the Middle Ages with attempts to conquer them by powerful states in the region. Erzurum entered into the Turkish-Islamic cultural rule by Saltuklu Principality after the Battle of Manzikert and lived one of its golden ages in every aspect during the domination of the Seljuk, following the Saltuks. The city was captured by theMongols in 1242 and was destroyed having lost some of its population during this period and returned to its days of prosperity within a considerably short time by beneting from the advantages of its position. In 1258, Erzurum continued its development and growth with the establishment of Azerbaijancentered Ilkhanid Empire and became one of the most popular trading cities in the Near East. This article investigates the ethnic, cultural and social transition of Erzurum during this era and ascertains its growth into one of the most crucial cities in the region.