Here are the latest updates and a map of the results.

Based on official results, the BBC projected that the Conservatives would win about 365 seats in the House of Commons, giving them a 74-seat majority. That should enable Mr. Johnson to lead Britain through Brexit in January, probably with an orderly deal as opposed to the crash-out that many had feared.

In a country that has “lurched from crisis to crisis” since voters narrowly chose Brexit in a 2016 referendum, two of our veteran correspondents write, Thursday’s result provides “a rare moment of piercing clarity.” It’s also a resounding vindication for a prime minister whose tenure has so far been marred by ceaseless upheaval.

The winners

Conservatives: The party was projected to win dozens of Labour seats in the industrial north and the Midlands, shattering the so-called red wall of support that has undergirded the Labour Party’s political fortunes for generations.

The currency: In a sign of relief that British politics would probably stabilize, the British pound rose as much as 2 percent as results began to trickle in, its strongest level since June 2018.

The losers

Labour : Analysts say the party’s apparent collapse — potentially its weakest electoral showing since before World War II — could take a decade or more to overcome. Its leader, Jeremy Corbyn, is likely to face calls to resign. Earlier today, Mr. Corbyn told reporters that he would not lead the party in “any future general election campaign.” But he vowed to stay on as leader for the time being to ensure a process “of reflection on this result and on the policies that the party will take going forward.”

Jo Swinson: The leader of the centrist Liberal Democrats, who was once seen as a potential kingmaker in Britain’s political scene, narrowly lost her parliamentary seat to a rival in the Scottish National Party.

Scotland’s future

The pro-independence Scottish National Party was projected to exceed expectations by winning 55 of Scotland’s 59 seats at Westminster, a 20-seat gain that puts the party in a position of almost total dominance in Scottish politics.

One result may be further calls for another vote on Scottish independence — and rising tensions between London and Edinburgh.