George IV continued Tamar's policy of strengthening of the Georgian feudal state. Georgia's largely isolationist policies had allowed it to accumulate a powerful army and a very large concentration of knights. He put down the revolts in neighbouring Muslim vassal states in the 1210s and began preparations for a large-scale campaign against Jerusalem to support the Crusaders in 1220. However, the Mongol approach to the Georgian borders made the Crusade plan unrealistic, as the reconnaissance force under the Mongols Jebe and Subutai destroyed the entire Georgian army in two successive battles, in 1221–1222, most notably the Battle of Khunan. Georgians suffered heavy losses in this war and the King George IV, himself was severely wounded. The Kingdom of Georgia itself was torn by internal dissent and was unprepared for such an ordeal. The struggle between the nobility and the crown increased. In 1222, King George appointed his sister Rusudan as a co-regent and died later that year. Queen Rusudan ( 1223–1245) proved a less capable ruler, and domestic discord intensified on the eve of foreign invasion.