The question of complex socio-political organization among pastoral nomadic groups has long posed a theoretical challenge for anthropologists, historians, and archaeologists alike. The problems arise from a disciplinary tendency to view pastoralists within a narrow economic and ecological framework but, in addition to this, the basic conception of 'complexity' has itself proven problematic. The definitions of complexity built originally upon systems theory and political economy place emphasis on organizational criteria derived primarily from sedentary societies with class stratification, intensive subsistence economies, and centralized administration. In this paper we argue that these classic definitions of complexity have not provided a good fit for analyzing the kinds of political organizations constructed by pastoral nomads of the Eurasian steppe zone. For that reason, we explore new ways of conceptualizing complex organization based on processes of integration, scale, and mobility. This approach offers a better explanation for material patterns documented across two neighboring valleys in northern Mongolia and provides substantial insight to the sub-regional polities preceding the rise of the Xiongnu state during the late first millennium BCE.