Britain’s departure from the European Union has arrived

Britain begins the day as a member of the European Union. Its status at the end of the day — as a proud nation that has reclaimed its sovereignty, or a diminished presence in Europe and the world — will still be up for debate.

The EU will have to bounce back from one of its biggest setbacks in its 62-year history to confront an ever more complicated world as its former member becomes a competitor, just across the English Channel.

Britain officially departed the EU at 11 p.m. local time Friday, midnight in Brussels. The departure comes 3½ years after the country voted by a margin of 52%-48% to walk away from the club that it had joined in 1973.

It’s the first time a country has left the EU, and many in the bloc rued the day. In Brussels, EU Commission President Ursula von der Leyen lamented that “as the sun rises tomorrow a new chapter for our union of 27 will start.”

But she warned Brexit day would mark a major loss for the U.K. and said the island nation is heading for a lonelier existence. “Strength does not lie in splendid isolation, but in our unique union.” Newspapers across the continent were marking the departure with headlines of “Adieu to Europe” and “Bye-Bye!” next to a Union Jack flag.

U.K. Prime Minister Boris Johnson was holding a Cabinet meeting in the pro-Brexit town of Sunderland, in northeast England. He was scheduled to deliver a pre-recorded address to the country an hour before departure, calling Brexit “not an end but a beginning.”

According to his office, he will describe it as “a moment of real national renewal and change.”

The government hopes the moment will be marked in a dignified, non-triumphalist fashion, with red, white and blue lights illuminating government buildings and a countdown clock projected onto the prime minister’s 10 Downing St. residence.

Inside, Johnson will gather with Cabinet ministers, aides, civil servants and Brexit campaigners for a reception featuring English sparkling wine and canapes including shortbread with English blue cheese and roast beef with Yorkshire pudding.

For the next 11 months, the EU and Britain already will be pitted against one another as they seek to negotiate a trade and security deal as part of their new relationship.

ANDREW TESTA / THE NEW YORK TIMES Anti-Brexit protesters gather outside Parliament in London on Friday as Britain prepared to formally withdraw from the EU.