Kazan is a city with a colourful, violent, complicated, rich history. Relations between the city and Russia, its gigantic neighbour to the north, were volatile for centuries, as Tatar troops invaded Russian lands and Russian armies (both temporal and spiritual) tried to take Tatar land and convert its Islamic population to Russian Orthodoxy. The attitude of the Russian rulers to the Tatars was varied: in the 16th century, Ivan the Terrible tried to forcibly convert the Tatars; in the mid-18th century, Empress Elizabeth decreed that all Tatar mosques in the city should be destroyed, leading to the razing of more than 400 mosques; and in the late 18th century, Catherine the Great allowed building of new mosques. Some mosques dating from this period still stand in the city.
