According to legend, after the 1552 conquest of Kazan, Tartar leaders who served under Tsar Ivan the Terrible requested that they be allowed to bury the Tatar dead in the Muslim manner. This was permitted and afterwards they placed a large boulder on the site so that it would be remembered. When foundations were being dug for a new mosque in 1801 the stone was found and the mosque was named İske Taş meaning 'old stone' in Tatar. It is also known as the Ninth Congressional Mosque. It was closed in 1931 and used as a store and a school, but reopened in 1994 after undergoing restoration work.