This paper will examine the evolution of Iberian efforts to secure religious, commercial, and political hegemony over the islands of the East Indonesian Archipelago and their subject populations, during the reign of Philip III, 1598-1621. Within the trajectory of current revisionism concerning Philip’s role in Spanish government, this paper argues that the affairs of empire in East and Southeast Asia provoked the king’s considerable interest. Iberian methods and aims in these distant imperial domains are found in the rich collections of archival documentation preserved in the Archivo General de Indias, the Arquivos Nacionais Torre do Tombo, and the Archivum Romanum Societatis Iesu. Evidence from these manuscript sources is supplemented by the vivid accounts of campaigns for conquest and conversion published in the early seventeenth century. These sources make it possible to examine Iberian diplomacy in the Southeast Asia within the broader context of Habsburg strategic goals for the maintenance of the security of other possessions in Asia, most notably the port-cities of