Note: Kazan' was occupied by the Mongols in the 13th century. It was sacked by Ivan III in 1469 and later by Ivan IV the Terrible in 1552. The city was burned in the peasant revolt of 1773-1774, and later rebuilt in a gridiron pattern by Catherine the Great. Kazan' is the site of a Tatar kremlin and the renowned Kazan State University, founded in 1804.