1973 enlargement of the European Communities

The 1973 enlargement of the European Communities was the first enlargement of the European Communities (EC), now the European Union (EU). Denmark, Ireland and the United Kingdom (UK) acceded to the EC on 1 January 1973. Gibraltar and Greenland also joined the EC as part of the United Kingdom and Denmark respectively, but the Faroe Islands, the British Overseas Territories and the Crown dependencies of the United Kingdom did not join the EC.

Ireland and Denmark both held referenda in 1972 in May and October respectively, and the UK held a referendum in 1975, on membership of the EC, all which approved membership of the EC. Norway planned to accede, but this was rejected in a referendum held in September 1972. Norway later reapplied to join, but voters again rejected the proposal in a 1994 referendum.

Greenland later withdrew from the EC on 1 January 1985 after a referendum in 1982. This was followed by the UK holding a referendum in 2016 on membership which resulted in the United Kingdom voting to leave the now EU.

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