The paper considers the princes of Muscovy not as distinct rulers of subject people, but as officers of the Golden Horde government. It will use this concept to trace their careers, considering questions of language and culture, focusing on Ivan I as a warrior serving Özbeg Khan and as provincial governor. His relationship with Özbeg will help frame the discussion, situating Muscovy and the Golden Horde as a single entity. This relationship will be traced through subsequent princes to conclude with the attempt to use the Khan’s authority to resolve the succession dispute between Vasily II and his uncle Yury. Despite functional Golden Horde authority having ended in 1395 there was no mechanism for defining legitimate authority other than the conceptual authority of the Khan. When the practical realities of Golden Horde rule were no longer a factor, the princes still existed in conceptual world were the office of Grand Prince existed as part of a Tatar system.