David Cameron last night fell on his sword, announcing there will be a staged exit from Number 10 and a new prime minister by October after he failed to keep Britain in the European Union.
He will go down in history as the prime minister who took Britain out of the EU despite so vociferously campaigning for the exact opposite.
Cameron promised to try to "steady the ship" over the next months.
"I do not think it would be right for me to try to be the captain that steers our country to its next destination," he said outside his Downing Street residence in London.
He said his successor should trigger the formal process for Britain to leave the European Union.
Former London Mayor Boris Johnson's fortunes have soared dramatically as the figurehead of Vote Leave.
He has neatly positioned himself to become a main player in any ensuing Conservative leadership challenge. Enter, Prime Minister Boris.
Johnson said Britons "have decided that it is time to vote to take back control from an EU that has become too remote, too opaque and not accountable enough to the people it is meant to serve".
Jeremy Corbyn's days as Labour leader may also be limited. He has been roundly criticised for not shouting loud enough about why Britain needed to remain an EU member. With 60 or 70 per cent of Labour members thought to be pro-EU, MPs will pile on the pressure for him to resign. It may be the moment that many of his opponents have been waiting for.
Meanwhile, Scottish First Minister Nicola Sturgeon said Scotland would "take all possible steps" to remain part of EU and would prepare legislation for a possible second referendum on independence.
It does not take much effort to work out who could be the main contenders to the Tories' top job.
While Justice Minister Michael Gove has said it does not interest him, it is not uncommon for politicians to change their minds. He is well-respected and managed to rise above personal attacks during the campaign, but some in the party worry that he is not "normal" enough.
Johnson, the other prominent eurosceptic, positioned himself well as a figurehead for the Brexit campaign and consistently polls well with Conservative members.
George Osborne, the Chancellor of the Exchequer, has slipped down the rankings in recent months though, while other Remain campaigners such as Theresa May and Sajid Javid do not perform well in polls.
PM's highs and lows
September 2014: Scotland rejects independence after Cameron makes a personal and impassioned plea and pledges to honour his promise to initiate substantial constitutional change in the UK. Alex Salmond's separatist campaign was resoundingly defeated, with 55 per cent of Scotland voting to remain in the 307-year-old Union. Cameron said that he was "delighted" that the Scottish people had rejected independence.
November 2014: Wage growth finally outstrips inflation - undermining Labour's "cost of living crisis". The increase in pay growth caught many City economists off-guard. The stubborn refusal of wages to rise above the rate of inflation has long been the missing element of the UK's economic recovery.
May 2015: The Conservative Party stormed to an unexpected outright win in the 2015 general election on one of the most dramatic nights in British electoral history. It was the majority that shocked the nation. After months of polling suggested that the Conservatives and Labour were neck-and-neck during the campaign, MPs applauded their Prime Minister for pulling off such a dramatic victory.
May 2010: David Cameron fails to win a majority and is forced to agree a deal with the Liberal Democrats to lead Britain's first coalition government since Second World II. It came as an embarrassment to the Conservative leader who was confident of winning an overall majority. Just days before he ruled out a Lib Dem alliance and pledged to go it alone.
March 2012: George Osborne's budget is dubbed the "omnishambles" over measures against pasties and caravans and Tories plummet in the polls from the fallout. The party was forced to do a U-turn over taxes on pasties, caravans and cathedrals. It was seen as a turning point in the last Parliament, which saw Labour taking a lead in the polls.
March 2016: Barack Obama accuses David Cameron of getting "distracted" over Libya and contributing to a "s*** show" and also implies that Cameron's rhetoric on Isis (Islamic State) has often outpaced his actions, rejecting the idea that strong language is a substitute for strength.