合丹，元太宗窝阔台的第六子。

合丹从拔都西征奇卜察克，遂入斡罗思。大军围秃里思城，不克，拔都派合丹与不里助攻，攻克屠城。1241年，分军五道，攻马加。合丹之军，从莫而陶逾山，入脱兰吾西而伐尼，选日耳曼六百人为向导。西行至滑拉丁，有内堡守御，城为木城。大军即破，俘戮无计。内堡仍坚守，大军退守，堡人出居外城，在军突返，都被杀害，以火炮攻陷内堡，老弱尽死。西攻生他马斯城，还是这样杀戮。别将被札纳忒城。至丕勒克，先驱马加人攻之，再驱斡罗斯及库清人继之，而督以蒙古兵，积尸盈堑，践之登城，攻七日，城陷。以届秋收，下令不杀人，敛民赋供军食。是年冬，合丹与拔都合兵渡秃纳河，围格兰城，架炮攻之，护以木栅，并填堑以进。城人焚居室，守礼拜堂以拒敌，其将为西班牙人，有勇略，相持末下。百太宗凶闻至。是时，合丹自率所部追马加王不剌不及，遂引兵与拔都东返。

Kadan (also Qadan) was the son of the second Great Khan of the Mongols Ögedei and a concubine. He was the grandson of Genghis Khan and the brother of Güyük Khan. During the Mongol invasion of Europe, Kadan, along with Baidar (son of Chagatai Khan) and Orda Khan (the eldest brother of Batu Khan and khan of the White Horde), led the Mongol diversionary force that attacked Poland, while the main Mongol force struck the Kingdom of Hungary.