A materialist political economy strain within theorizing social complexity in the Pacific has been evident at least since Marshall Sahlins’s 1958 Social Stratification in Polynesia. It developed further through contributions from anthropologists Irving Goldman and Jonathan Friedman, before being taken up by archaeologists in the early 1980s. Feeling that progress had stalled somewhat in the further development of such an approach as we entered the second decade of this century, Tim Earle and myself sought in 2015 to bring the political economy approach in Pacific archaeology into dialogue with developments in archaeological theory over the previous decade or so. The engagement with related theoretical approaches continued in a wider collaboration of 2019 with Martin Furholt, Colin Grier, and Tim Earle again. The chapter discusses this history of Pacific political economy approaches as the necessary background in posing the question of whether a unified theory of colonization, exchange, and social complexity can be constructed. It canvasses a mixture of factors that drove seaborne migration across what is now a largely Austronesian-speaking third of the world’s surface, the Pacific Ocean. Longstanding cultural and social patterns determined temporary alliances between elite factions and commoners that allowed fission of communities to take place. Developments in sea transport technologies capable of long-distance transportation for founding populations gave added impetus for maritime colonizing expeditions that ended up reaching almost every Pacific island capable of sustaining human life. Common themes of the interplay of island size, resources, and connectivity or isolation helped determine the outcome of settlement in terms of the possibilities and limits available for particular sociopolitical forms to evolve and sustain themselves.