When Činggis Qan died in 1227, the Mongol Empire was a confederation of steppe peoples engaged in conquests over other steppe societies as well as civilizations of Central Eurasia. By the time of the election of Činggis Qan’s grandson, Möngke, to the office of qa’an in 1251, the Mongol Empire had become a loosely allied group of states that recognized the qa’an as the head of an administration whose main duties were the collection and redistribution of wealth. The transformations that took place in the Mongol Empire between 1227 and 1251 saw the ebb of collective sovereignty as an effective ruling structure and a shift toward regional centers of power based upon local needs and coinciding with the four appanages into which Činggis Qan had divided his conquests among four of his sons. Contrary to existing scholarship that frames 1227-51 as a period of decline and dissolution, this dissertation considers Činggis Qan’s successor, Ögödei (r. 1229-41), and his heirs as actors in a transitional phase of the Mongol state characterized by a waning of collective rule of the unified Mongol confederation and an accretion of authority in the office of qa’an. Key to understanding this period as one of transition as opposed to decline is a reexamination of the Mongols’ intentions behind state-building activities and development of administrative institutions. This dissertation challenges existing notions of the Toulid coup as a dynastic exchange of power and, instead, conceives the election of Möngke as an attempt to salvage a unified confederacy and reestablish the mechanisms of collective sovereignty and its constituent infrastructure for the redistribution of wealth among Mongol elite. Finally, this dissertation presents a narrative of the lives of Ögödei, Töregene (r. 1242-46), Güyük (r. 1246-48), and Oghul Qaimiš (r. 1248-51), all of whom occupied the seat of qa’an and are not generally understood to be influential protagonists in the early Mongol Empire. Furthermore, 1227-51 is considered an era consisting of coherent and interrelated elements with discernible characteristics that make it distinct from what came before 1227 and after 1251.