This study combines long-term settlement data with short-term excavation data to explore the conditions that led late prehistoric communities in Iberia’s southwest to aggregate during the Late Bronze Age [LBA]. This long-term approach involves the application of geographic information systems [GIS] to identify settlement patterns in the Central Alentejo from the Late Neolithic [LN]/Chalcolithic to the Late Bronze Age (ca. 3500 – 800 BCE). In the Serra d’Ossa microregion of the southwest there are 176 sites that date to the Neolithic/Chalcolithic, only two that date to the EBA/MBA, and 27 that date to the LBA. This shift is directly related to the Chalcolithic “collapse” that occurred in the mid/late third millennium BCE, influenced by both sociocultural and environmental factors. The LBA of the southwest has long been defined by the emergence of a new culture associated with a concern for defensiveness and warriorship, represented on stone stelae by warrior iconography, and by the emergence of large-fortified upland sites that appear during this period. A distinct lack of small-scale settlement data has previously led to insufficient interpretations and characterizations of the period. In turn, this thesis incorporates short-term data from excavation at the large-fortified upland site of Castelo Velho da Serra d’Ossa, the one excavated example of such a site in the Serra d’Ossa microregion and one of the few excavated LBA sites in the wider southwest. The short-term excavation data are discussed in the context of the long-term settlement patterns to better characterize the LBA of the Iberian southwest, a period previously underrepresented in the region. The central focus of study is to investigate the emergence of these settlements (up to 15 ha in size) and the communities that inhabited them; considering the processes underpinning place-making and aggregation both locally and within its broader prehistoric context. / Thesis / Master of Arts (MA)