Detailed Instructions: In this task you will be given a text passage from a trivia quiz. You should choose the category this question belongs to from these categories: History, Science, Social Science, Fine Arts, Literature. You can only choose one category, so if in doubt, please choose the closest match.
Q: This rulers chief justice was Shigi Qutuqu, and he also appointed the minister Yel Chucai. An account of travels to this rulers court was published as the Journey to the West of the Taoist monk Kiu Chang Chun. This promulgator of the Yasa law code was served by the general Jebe, who died soon after a victory at the Battle of the Kalka River. A prime source for this rulers life is a Secret History, and he rose to power by allying with the Kerait ruler Toghrul before fighting a power struggle with Jamuka. This ruler conquered the Khwarezmid Empire and invaded the Tangut kingdom of Western Xia. This mans general Subotai would go on to serve his son and successor, Ogdi. For 10 points, name this conqueror, born Temjin, who united the steppe tribes and founded the Mongol Empire.
A:
History