When did Brexit happen?

In the 2016 referendum, 51.9 percent of voters chose Leave and 48.1 percent Remain, on a turnout of 72.2 percent. Prime Minister David Cameron, who had campaigned to stay, resigned the next day. The UK formally triggered Article 50, the EU’s exit clause, on 29 March 2017, beginning years of negotiations and several missed deadlines. Britain left the EU at 11 p.m. UK time on 31 January 2020, and new trade arrangements took effect when the transition period ended on 31 December 2020. The UK became the first country to leave the EU, after 47 years of membership.