Brexit (ˈbrɛksᵻt,_ˈbrɛgzᵻt; portmanteau of "British exit") was the withdrawal of the United Kingdom (UK) from the European Union (EU) at 23:00 GMT on 31 January 2020 (00:00 1 February 2020 CET). The UK is the only sovereign country to have left the EU. The UK had been a member state of the EU or its predecessor the European Communities (EC), sometimes both at the same time, since 1 January 1973. Following Brexit, EU law and the Court of Justice of the European Union no longer have primacy over British laws.
The Common Travel Area (CTA; Comhlimistéar Taistil, Ardal Deithio Gyffredin) is an open borders area comprising the United Kingdom, Ireland, Isle of Man, and the Channel Islands. The British Overseas Territories are not included. Based on agreements that are not legally binding, the internal borders of the CTA are subject to minimal controls and can normally be traversed by British and Irish citizens with minimal identity documents (with certain exceptions).
Between 2017 and 2019, representatives of the United Kingdom and the European Union negotiated the terms for Brexit, the planned withdrawal of the UK from the EU. These negotiations arose following the decision of the Parliament of the United Kingdom to invoke Article 50 of the Treaty on European Union, following the UK's EU membership referendum on 23 June 2016. The negotiating period began on 29 March 2017, when the United Kingdom served the withdrawal notice under Article 50.
The Republic of Ireland–United Kingdom border, sometimes referred to as the Irish border or British–Irish border, runs for from Lough Foyle in the north-west of Ireland to Carlingford Lough in the north-east, separating the Republic of Ireland from Northern Ireland. Border markings are inconspicuous, in common with many inter-state borders in the European Union.
Border control refers to measures taken by governments to monitor and regulate the movement of people, animals, and goods across land, air, and maritime borders. While border control is typically associated with international borders, it also encompasses controls imposed on internal borders within a single state. Border control measures serve a variety of purposes, ranging from enforcing customs, sanitary and phytosanitary, or biosecurity regulations to restricting migration.
