section_path: Member states/Former members
section_name: Former members
paragraph_text: Former members
  
  Article 50 of the Lisbon Treaty provides the basis for a member to leave the EU. Two territories have left the union: Greenland (an autonomous province of Denmark) withdrew in 1985; the United Kingdom formally invoked Article 50 of the Consolidated Treaty on European Union in 2017, and became the only sovereign state to leave when it withdrew from the EU in 2020.