Throughout the Middle Ages, the history of the Iberian Peninsula was shaped by the arrival of Arabs and the spread of Islam, as well as by the military campaigns of Christian groups advancing southwards. The resulting frontier fluctuated in both size and location, gradually moving southwards across the peninsula and creating a large transitional zone between the political spheres of Asturias-León, Portugal and Castile on one side, and Al-Andalus on the other.

While traditional studies have focused on military and repopulation strategies, archaeology has filled important gaps in our knowledge that documentary sources could not. This frontier region has a complex history of conflict, as evidenced by the construction of fortifications. Yet during periods of relative peace, it also fostered significant cultural interactions and acculturation processes, enabling the emergence of a dynamic and multifaceted society. These territories were characterised by significant social mobility, including migratory movements, repopulation efforts, trade, the exchange of knowledge, and the creation of new agricultural landscapes.

This session welcomes archaeological research of defensive structures, battles and settlements, as well as bioarchaeological studies of paleodemography, genetics, health and diet.