Druguse
The siege of Kozelsk was one of the main events of the Western (Kipchak) March of the Mongols (1236–1242) and the Mongol invasion of Kievan Rus' (1237–1240) at the end of the Mongol campaign in northeastern Kievan Rus' (1237–1238). The Mongols laid a siege in the spring of 1238 and eventually conquered and destroyed the town of Kozelsk, one of the subsidiary princely centers of the Principality of Chernigov.