Portugal–Spain border Portugal–Spain border The Portugal–Spain border is the international boundary between Portugal and Spain. Referred to as "la Raya" in Spanish and "A Raia" in Portuguese (the stripe), the current demarcation is almost identical to that defined in 1297 by the Treaty of Alcañices. It is one of the oldest borders in the world. The Portugal–Spain border is 1,214 km (754 miles) long and considered the longest uninterrupted border within the European Union. The border is not defined for 18 km (11 miles) between the Caia river and Ribeira de Cuncos, because of the disputed status of Olivenza, which has been
Portugal I of Portugal signed with the king Fernando IV of Castile (which was represented, when being a minor, by his mother the queen Maria de Molina) the Treaty of Alcañices (1297), which stipulated that Portugal abolished agreed treaties against the kingdom of Castile for supporting the infant Juan de Castilla. This treaty established inter alia the border demarcation between the kingdom of Portugal and the kingdom of Leon, where the disputed town of Olivenza was included. The reigns of Dinis I (Denis I), Afonso IV (Alphons IV), and Pedro I (Peter I) for the most part saw peace with the