This contribution presents a political model for interpreting the large Copper Age settlements of the Iberian Peninsula. It considers that factional competition within segmentary societies creates conditions that both promote aggregational processes and undermine them (frequently leading to group fission). The critical moment when factional leaders may consolidate their power is the initial mobilization of a collective workforce. If such consolidation fails to take place, factional competition and the development of household interests multiplies the fronts on which resistance to leaders can take place. This model is applied to the archaeological record of the Upper Guadalquivir. The results of this analysis suggest that the dynamics of large-scale aggregation only can develop in places were there exists a sufficiently large population, abundant potential resources, and the technology by which resources and population can be exploited and maintained. A model that will explain the variability observed in the Iberian Copper Age must also consider political factors, however.