United Kingdom membership of the European Union

The United Kingdom (along with the British Overseas Territory Gibraltar) was a member state of the European Union (EU) and of its predecessor the European Communities (EC) - principally the European Economic Community (EEC) from 1 January 1973 until 31 January 2020. Since the foundation of the EEC, the UK had been an important neighbour and then leading member state, until Brexit ended 47 years (17,196 days) of membership. During the UK's time as a member state two referendums were held on the issue of its membership, with the first being held on 5 June 1975, resulting in a vote to stay in the EC, and the second, held on 23 June 2016, which resulted in the vote to leave the EU.

The flags of the European Union and the United Kingdom.