The province of Guadalajara in central Iberia represents a suitable territory for analyzing the dynamics of long-term settlement patterns during the Middle Ages, a period characterized by multiple waves of conquest and colonization processes. Since the Late Roman period and the organization of the Visigothic Kingdom, the settlement network was restructured with the creation of new cities and episcopates, and the maintenance of rural sites in the fertile river valleys. Starting in 711 CE with the Islamic conquest of Iberia and the formation of al-Andalus, a new picture of rural settlement emerges with small and medium-sized settlements. These are associated with irrigated fields and organized around fortifications (including single towers) that became more important during the centuries in which these lands functioned as political frontiers. From the 12th century, when this region was conquered and colonized by Christian societies, a new network of towns was consolidated that still exists today, structured around the great fortifications that were the capitals of the comunidades de villa y tierra (communities of “towns and lands”). This paper integrates all existing information on long-term population dynamics in this region, discussing the impact and role of settlers in each period, the economic and political changes that are reflected in the landscape, as well as the influence of local geology, hydrology and topography.