Fire of Moscow
In the later years of Ivan's reign, the southern borders of Muscovy were disturbed by Crimean Tatars, mainly to capture slaves. (See also Slavery in the Ottoman Empire.) Khan Devlet I Giray of Crimea repeatedly raided the Moscow region. In 1571, the 40,000-strong Crimean and Turkish army launched a large-scale raid. The ongoing Livonian War made Moscow's garrison to number only 6,000 and could not even delay the Tatar approach. Unresisted, Devlet devastated unprotected towns and villages around Moscow and caused the Fire of Moscow (1571). Historians have estimated the number of casualties of the fire to be 10,000 to 80,000.