Brexit took place on Jan. 31, 2020, when the U.K. legally revoked its membership in the 28-nation EU. Voters had supported the move by 52% to 48% more than three years earlier, after a rancorous 10-week campaign that exposed anxieties about globalization and raised questions about the consequences for a united Europe. The vote jolted financial markets, sending the U.K. currency tumbling on the prospect of years of uncertainty about how Brexit will work. Younger citizens and residents of cosmopolitan London voted overwhelmingly to remain in the EU. So did people in Scotland. U.K. Prime Minister David Cameron resigned after the surprise result and was replaced by Theresa May, who triggered the complex and chaotic process of negotiating Britain’s exit from the bloc. The wrangling didn’t end until another prime minister, Boris Johnson, won a general election on the promise to get the job done. After Brexit, the U.K. and the EU entered into an 11-month transition period and set a new deadline of December 2020 to unwind agreements in areas as diverse as fishing quotas, financial services and safety standards.