Throughout the period of the Ottoman territorial expansion in the Balkans, military commanders from the families of several frontier lords figured prominently during conquests and emerged as distinct frontier elites and sociopolitical entities in their own right. As hereditary leaders of the vanguard Ottoman forces the frontier lords were in an extremely advantageous position to staff their courts and armies with slaves acquired through conquests in non-Muslim territories. These captives were raised, trained, and acculturated as part of the military-administrative households of the frontier lords, and in turn contributed to conquest, becoming the spearhead of further military expeditions. This essay examines the composition of the extended military household of Mihaloğlu Mehmed Beg, a district governor of Niğbolu, as presented in an Ottoman register from the second decade of the 16th century and argues that his personal retainers became a reservoir for the military and the administration of the marcher district under his governance. It further maintains that the frontier lords’ households, which represent a distinct group of power holders outside the sultanic dynasty, emerged as true loci of power that managed manpower along the bordering regions and should be studied in regards not only to their regional authority, but to their place in the Ottoman political establishment as well. By establishing stable patron‒client relations with the members of their extended households, the frontier lords found themselves at the apex of a large web of networks entwined within social, military, administrative, political, and cultural life along the borders of the Ottoman state and should be regarded as an indispensable part of the Ottoman socio-political order in the region as a whole.