The Galicia–North Portugal Euroregion is a cross-border Euroregion straddling Galicia (Spain) and the North Region (Portugal). It was established in 2008. This inter-regional co-operative effort has been shaped and justified both by the economic potential of a reinforced co-work of nearby northern Portuguese and Galician industrial core cities as well as by the historical, cultural and ethnolinguistic past that both territories traditionally shared and whose idiosyncrasy survived, although somewhat diluted, until our times. These common economic, political, cultural and societal ties can be traced back at least to the late Bronze Age, before the Romanization of northwestern Iberia and when the Castro Culture evidenced a common identity and heritage in this geographical area. With the Romanization of these societies, their shared identity has been somewhat reflected and respected through the geo-culturally explained extension of the Roman province of Gallaecia. These far west populations tepidly and very gradually adapted to the manners and modus vivendi of the Romans, in what some historians considered to be a pacific co-habitation of different social realities. The lack of severe conflicts between the two different identities assured a relatively suitable cultural transition to the Middle Ages. After the dissolution of the Western Roman Empire, multiple geopolitical and strategical decisions impacted on one way or another in the organic continuation of this geographical and cultural region, although never as definitive as to break their historical attachment. It was during the Early and High Middle Ages that successive kingdoms, all of them related to the northwestern Christian Kingdoms that evolved during the early stages of the Reconquista, replaced one another depending on the location of the kingdom's seat, although both the North of Portugal and Galicia remained united and eventually formed the Kingdom of Galicia. Similarly, Galicia and the north of Portugal remained a cultural and social fairly well defined continuum. However, by the 9th century the political unity of both territories already started to fade out when the title of count was given to the nobleman Vímara Peres by Alfonso III of Asturias after his successful campaign in the reconquest of Portus Cale (Porto). This landmark turned out decisive for the political fragmentation of both territories, leading to the formation of the County of Portugal. Although originally conceived as a vassalage of the Kingdoms of Asturias, Galicia and León, by the late 11th century it was reestablished after an increase of its counts power and finally