Long analyzed as biopolitics, the regulation of population always entailed geopolitics as well, although tracing the connections and separations of these strands across time, and across political cultures, is not easy. To appreciate the many dimensions of population in world history, a new approach is needed; something like an integrated and global gendered political economy of population. Considered at a global level, the eighteenth and nineteenth-century expansion of Europe was both demographic and geographic. The politics of fertility decline as it played out in international and racial relations has received much historical analysis, and within many different national traditions. The fertility decline has been read as depopulation. Imperial German scholars and statesmen had been deeply interested in population density, overpopulation, before and during the First World War. European demographic history was the main focus for European and non-European economists, both the massive population growth of the nineteenth century and the localized fertility declines.