European Union representation within those institutions, a practice often referred to as "pooling of sovereignty". To become a member, a country must meet the Copenhagen criteria, defined at the 1993 meeting of the European Council in Copenhagen. These require a stable democracy that respects human rights and the rule of law; a functioning market economy; and the acceptance of the obligations of membership, including EU law. Evaluation of a country's fulfilment of the criteria is the responsibility of the European Council. No member state has yet left the Union, although Greenland (an autonomous province of Denmark) withdrew in 1985. Article 50 of
Basque Country (autonomous community) tribunals ruled in their favour. The Basque Government replaced it with an empty red field. Navarre is one of the historical Basque territories and even claimed by the Basque nationalists as the core of the Basque nation. There are also two enclaves surrounded by Basque territory—Treviño (Basque: "Trebiñu") and Valle de Villaverde (Basque: "Villaverde-Turtzioz")—which belong to the fellow neighbouring communities of Castile and León and Cantabria respectively, for which a legal connection to the Basque Country has become an on-off matter of political discussion. The Basque Autonomous Community ranks first in Spain in terms of per capita income, with a