The Armenian general Smbat Bagratuni's remarkable rise to military and political preeminence in the late sixth- and early seventh-century Sasanian Empire presents a fascinating historical question: how did a liminal figure, a Christian from a frontier region, become the “Joy of Ḵusrō” and “Warrior of the Lords” of king Ḵusrō II Aparvēz (590–628 CE)? This essay argues that Bagratuni's accomplishments were rooted in Sasanian patterns of political decentralization, provincial regionalism and strategic politics. The Sasanians were ethnically Persian, but Parthian and Armenian aristocrats from the periphery of the empire played a central role in upholding the regime. Granting titles, wealth and personal support, the king sought to turn aristocratic families against each other to enhance royal authority. Simultaneously, regional aristocrats like Smbat Bagratuni used royal patronage to advance their local interests, often at the expense of the royal center. The life of Smbat Bagratuni illustrates how complex negotiations of individual and collective identity shaped relations of “center” and “periphery” in Sasanian Iran.