This essay discusses the main lines of current research on the social and economic history of the early modern Iberian worlds. It then goes on, in light of recent debates, to make the case for the value of a purposeful dialogue between global history and imperial history. The issues of primary concern here are the extent to which lateral, inter-regional relations in the Iberian worlds dominated vertical relations connecting particular areas to Madrid or Lisbon; how power and agency on local scales may be integrated into accounts of flows and interactions on larger scales; the ways in which the history of the Iberian empires through a global prism breaks with pre-existing nationalistic narratives; and whether or not the decentralized component of these empires was unique to them. Finally, examples are detailed of how Iberian imperial history can provide a fruitful basis for a polycentric history of globalization. The examples given take heart from critical engagement with the Great Divergence paradigm, the new analytical potentialities of global ecological history, the constructive and destructive impact of globalization upon empires, and the importance of studying the history of empires comparatively.