The island of Sardinia is a meeting point for three continents, receiving a constant migration since prehistoric times. The migration from the Iberian Peninsula was permanent and consistent between the 12th and 15th, as stated in Italian and Spanish sources. In this framework, our approach analyse the internal and external mobility of the population and the intense movement of people, ideas and goods that have profoundly marked the different territorial and urban features of the island. The paper shows the different sizes and types of Iberian migrations in Sardinia and emphasizes the distinction between the first migration (those who migrated to Sardinia taking part in the military conquest of the island by the Infante Alfonso) and the second one (those who participated in the subsequent occupation and domination of the island).