International
Whilst the Disputed status of Gibraltar with the United Kingdom is perhaps the best known territorial dispute of Spain. Spain has a territorial dispute with Morocco concerning the five places of sovereignty (plazas de soberanía) on and off the coast of Morocco - the coastal enclaves of Ceuta and Melilla, which Morocco contests, as well as the islands of Peñon de Alhucemas, Peñon de Vélez de la Gomera, and Islas Chafarinas. Portugal continues to claim Olivenza/Olivença, asserting that under the Vienna Treaty of 1815, Spain recognized the Portuguese claims as "legitimate". The historic disputes with Portugal over the Savage Islands in the Atlantic Ocean were resolved in recent times.
The strategic position of the Strait of Gibraltar has left a legacy of a number of sovereignty disputes. Spain maintains sovereignty over Ceuta, Melilla, Penon de Velez de la Gomera, Alhucemas and the Chafarinas Islands (captured following the Christian reconquest of Spain) based upon historical grounds, security reasons and on the basis of the UN principle of territorial integrity. Spain also maintains that the majority of residents are Spanish. Morocco claims these territories on the basis of the UN principles of decolonisation, territorial integrity and that Spanish arguments for the recovery of Gibraltar substantiate Morocco’s claim.
Olivenza (Spanish) or Olivença (Portuguese) is a town and seat of a municipality, on a disputed section of the border between Portugal and Spain, which is claimed de jure by both countries and administered de facto as part of the Spanish autonomous community of Extremadura. The population is 80% ethnic Portuguese and 30% of Portuguese language. Olivenza/Olivença had been under continuous Portuguese sovereignty since 1297 when it was occupied by the Spanish in 1801 and formally ceded by Portugal later that year by the Treaty of Badajoz. Spain claims the de jure sovereignty over Olivenza/Olivença on the grounds that the Treaty of Badajoz still stands and has never been revoked. Thus, the border between the two countries in the region of Olivenza/Olivença should be as demarcated by that treaty. Portugal claims the de jure sovereignty over Olivenza/Olivença on the grounds that the Treaty of Badajoz was revoked by its own terms (the breach of any of its articles would lead to its cancellation) when Spain invaded Portugal in the Peninsular War of 1807.
Portugal further bases its case on Article 105 of the Treaty of Vienna of 1815, which Spain signed in 1817, that states that the winning countries are to "endeavour with the mightiest conciliatory effort to return Olivenza/Olivença to Portuguese authority". Thus, the border between the two countries in the region of Olivenza/Olivença should be as demarcated by the Treaty of Alcanizes of 1297. Spain interprets Article 105 as not being mandatory on demanding Spain to return Olivenza/Olivença to Portugal, thus not revoking the Treaty of Badajoz. Portugal has never made a formal claim to the territory after the Treaty of Vienna, but has equally never directly acknowledged the Spanish sovereignty over Olivenza/Olivença.
Spanish public opinion is not generally aware of the Portuguese claim on Olivenza/Olivença (in contrast to the Spanish claim on Gibraltar or the Moroccan claims on Ceuta, Melilla and the Plazas de soberanía). On the other hand, awareness in Portugal has been increasing under the efforts of pressure groups to have the question raised and debated in public.
Read more about this topic: Foreign Relations Of Spain, Disputes