and Chang'an, which were now ruled by the Mongols. In addition to the war with the Jin dynasty, Ögedei crushed the Eastern Xia founded by Puxian Wannu in 1233, pacifying southern Manchuria. Ögedei subdued the Water Tatars in the northern part of the region and suppressed their rebellion in 1237. Conquest of Georgia and Armenia The Mongols under Chormaqan returned to the Caucasus in 1232. The walls of Ganjak were breached by catapult and battering ram in 1235. The Mongols eventually withdrew after the citizens of Irbil agreed to send a yearly tribute to the court of the khagan. Chormaqan waited until 1238, when the force of Möngke Khan was also active in the north Caucasus. After subduing Armenia, Chormaqan took Tiflis. In 1238, the Mongols captured Lorhe whose ruler, Shahanshah, fled with his family before the Mongols arrived, leaving the rich city to its fate. After putting up a spirited defense at Hohanaberd, the city's ruler, Hasan Jalal, submitted to the Mongols. Another column then advanced against Gaian, ruled by Prince Avak. The Mongol commander Tokhta ruled out a direct assault and had his men construct a wall around the city, and Avak soon surrendered. By 1240, Chormaqan had completed the conquest of Transcaucasia, forcing the Georgian nobles to surrender. Korea In 1224, a Mongol envoy was killed in obscure circumstances and Korea stopped paying tribute. Ögedei dispatched Saritai qorchi to subdue Korea and avenge the dead envoy in 1231. Thus, Mongol armies began to invade Korea in order to subdue the kingdom. The Goryeo King temporarily submitted and agreed to accept Mongol overseers. When they withdrew for the summer, however, Choe U moved the capital from Kaesong to Ganghwa Island. Saritai was hit with a stray arrow and died as he campaigned against them. Ögedei announced plans for the conquest of the Koreans, the Southern Song, the Kipchaks and their European allies, all of whom killed Mongol envoys, at the kurultai in Mongolia in 1234. Ögedei appointed Danqu commander of the Mongol army and made Bog Wong, a defected Korean general, governor of 40 cities with their subjects. When the court of Goryeo sued for peace in 1238, Ögedei demanded that the king of Goryeo appear before him in person. The Goryeo king finally sent his relative Yeong Nong-gun Sung with ten noble boys to Mongolia as hostages, temporarily ending the war in 1241. Europe The Mongol Empire