The Tokhtamysh–Timur war saw a marked decline in its fortunes. It was sacked by Bulaq-Temir in 1361, endangered by Timur, looted by Russian pirates (ushkuiniki), and destroyed in 1431 by Vasily the Blind of Muscovy. As a Muslim religious center Bolgar persevered until the mid-16th century when the Khanate of Kazan was conquered by the Russian Czar Ivan IV and incorporated into the Russian state.