greater participation of territorial communities in the progress of Europe, the development of border regions and the search for greater cooperation between all territorial entities in matters such as regional, urban and rural development, environmental protection or the improvement of shared infrastructures.

On 21 May 1981, the European Framework Convention on Cross-Border Cooperation between Communities or Territorial Authorities, also known as the Treaty of Madrid, was adopted in Madrid, which constitutes the legal basis for such cooperation. It entered into force generally on 22 December 1981 and the Member States began to ratify it thereafter. The Framework Convention entered into force in Spain on 25 November 1990, following its ratification.

Under the Framework Convention, Spain has signed two international treaties regulating cross-border cooperation: the Bayonne Treaty with France, in force since 1997, and the Valencia Treaty with Portugal, in force since 2004.

During these years, more than sixty agreements have been signed. Some are exclusively local (27); others are exclusively regional (22); some are mixed regional-local (11), and two regional conventions have been signed by more than one Autonomous Community. The agreements signed under the Spanish-French Treaty add up to a total of 33; slightly more than the 29 signed under the Spanish-Portuguese Treaty.

On the other hand, it should be noted that since 2004, the participation of the Autonomous Communities in the Bilateral Summits between the border states (France, Portugal and Morocco) has also been enhanced.