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With 10 Downing Street lit up in red and blue, the departure of the United Kingdom from the European Union became official at 11 p.m. GMT Friday. It took three years from a first narrow vote for Brexit, but after a second referendum and a few changes in leadership, it finally happened.

Prime Minister Boris Johnson released a video statement lauding this "moment" many people "thought would never come," and promised to "turn this opportunity into a stunning success." Johnson guaranteed a vote in favor of Brexit after he ordered an election late last year, which his Conservative party won handily.

Still, Britain is sharply divided on Brexit, with larger cities, Northern Ireland, and especially Scotland still in favor of remaining in the EU. That was apparent in London, where Mayor Sadiq Khan ran projections emphasizing that the city was still an open, welcoming place.

Britain and the EU have agreed that the U.K. will retain all EU rules for 11 months while the two sides hammer out a new trade relationship and other guidelines for their new relationship.