Prime Minister Theresa May has unveiled a nearly completely new look cabinet, in a major departure from predecessor David Cameron's top team.
George Osborne, Michael Gove, John Whittingdale, Nicky Morgan and Oliver Letwin have all been sacked by Mrs May.
Liz Truss is justice secretary, Justine Greening takes education and Tory leadership contender Andrea Leadsom has been promoted to environment secretary.
Boris Johnson became foreign secretary. Philip Hammond was made chancellor.
Eurosceptic David Davis, meanwhile, will take charge of negotiating Britain's exit from the European Union, in a newly created post of Brexit secretary.
In another new post announced on Wednesday, Liam Fox was appointed as the new international trade secretary. Amber Rudd - formerly the energy secretary - took over Mrs May's former role as home secretary.
The current male-female ratio of the cabinet remains roughly the same - at 70% to 30%, while there are 16 cabinet members, including Mrs May, who backed Remain, and seven who campaigned for Brexit.
Just four cabinet positions have stayed in the same hands: Defence Secretary Michael Fallon, Health Secretary Jeremy Hunt, Welsh Secretary Alun Cairns and Scottish Secretary David Mundell.
Former Conservative Foreign Secretary Sir Malcolm Rifkind praised the "ruthless" way Mrs May has appointed her top team, saying it showed strong leadership and "strategic" vision.
"She has not only got a strategy to balance the Leave and Remain sides, she is trying to eliminate these distinctions because we are all now aiming for the same objective. She has appointed with a ruthlessness that has been impressive to look at," he told the BBC.
"The decision that most surprised me was George Osborne - not that he ceased to be chancellor - but it appears she wasn't even willing to offer him a job in government.... he is a very impressive heavyweight."
Sir Malcolm, who was a minister under Margaret Thatcher and John Major, said Boris Johnson's appointment as foreign secretary was "risky" because the qualities that make him popular with the public did not necessarily make him a good diplomat.
There were some big promotions for Home Office ministers James Brokenshire and Karen Bradley, who were appointed Northern Ireland secretary and culture, media and sport secretary, respectively.
Damian Green, a former justice and Home Office minister, was elevated to work and pensions secretary, while Brexit campaigner and ex-work and pensions minister Priti Patel was promoted to international development secretary.
There were also some resignations. Tory leadership contender and Work and Pensions Secretary Stephen Crabb stepped down from government "in the best interests of my family", while Northern Ireland Secretary Theresa Villiers resigned after turning down the offer of another role.
In other developments:
- Patrick McLoughlin was moved from transport secretary to Conservative Party chairman
- Sajid Javid - formerly business secretary - is now the communities and local government secretary
- Chris Grayling - who was Mrs May's leadership campaign chief - takes up the post of transport secretary. He was previously Commons leader
- Baroness Evans has taken up the post of Leader of the House of Lords
- Former policing and justice minister Damian Green becomes work and pensions secretary - replacing Stephen Crabb who resigned
- Attorney General Jeremy Wright - who attends cabinet - stayed in his post
- Gavin Williamson, a former parliamentary private secretary to David Cameron, was appointed government chief whip
- The Department for Business, Innovation and Skills becomes the Business, Energy and Industrial Strategy (BEIS) department - led by Greg Clark, formerly communities and local government secretary
- As a result, the Department for Energy and Climate Change has been scrapped, its brief folded into BEIS
- The Department for Education will take on higher and further education, skills and apprenticeships, bringing it together so there is a comprehensive end-to-end view of skills and education
Justice Secretary Michael Gove - who was one of the leading figures in the campaign to leave the EU and a Tory leadership contender - was the first to be sacked on Thursday morning, losing his job to Ms Truss- the first female Lord Chancellor in the near 1,000-year history of the role.
Former Labour leader Ed Miliband criticised the closure of the Department for Energy and Climate Change as "just plain stupid", Green MP Caroline Lucas said it was a "deeply worrying move", and Lib Dem leader Tim Farron called it was a "backward" decision which "clearly downgrades our commitment to tackling climate change".
The move also drew criticism from the SNP's Angus MacNeil, who chairs the Commons Energy and Climate Change Committee which shadows the department. He said it raises "urgent questions", such as over who will be responsible for the UK's legal obligation to reduce its carbon emissions.
Former Labour shadow home secretary Yvette Cooper called the cabinet "very right-wing" and suggested this was at odds with Mrs May's words outside No 10 on Wednesday, saying there was often a "very big gap between the rhetoric and the reality with Theresa May".
Earlier, the new chancellor, Mr Hammond, said there would be "no emergency Budget" when asked about his first priorities as chancellor.
His predecessor George Osborne warned during the EU referendum campaign that he would have to cut public spending and increase taxes in an emergency Budget if there was a vote for Brexit.
Mr Hammond said he would make "carefully considered decisions over the summer", followed by an Autumn Statement "in the normal way".
The chancellor also told BBC Radio 4's Today that the vote to leave the EU had "shaken confidence" in the UK economy and "caused many businesses to pause investment decision".
He said the government now needed to "send signals of reassurance about the future as quickly and as powerful as we can".
In a move that surprised the political world, Mrs May put Mr Johnson - one of the most prominent figures of the campaign to leave the EU - in charge of the Foreign and Commonwealth Office.
Mr Johnson, who has said he was "very humbled" and "very proud" at the appointment, is no stranger to controversy - or gaffes - on the international stage.
During the EU referendum campaign, he drew criticism for comments he made about US President Barack Obama, who he said had an "ancestral dislike" of the UK because of his "part-Kenyan" heritage.
In 2015, Mr Johnson had to cancel planned public events in the West Bank because of security fears after he criticised backers of a boycott on Israeli goods, and he has previously described Hilary Clinton - US presidential hopeful - as having "a steely blue stare, like a sadistic nurse in a mental hospital".
The cabinet appointment throws Mr Johnson a lifeline after a turbulent couple of weeks which saw his Tory leadership bid torpedoed by fellow Brexit campaigner Mr Gove.
In his first comments since taking up the post, Mr Johnson set out his vision for Britain to be a more "global player", and he said Brexit did not mean the UK was leaving Europe.
However, Liberal Democrat leader Mr Farron predicted the new foreign secretary would "spend more time apologising to nations he's offended" than carrying out the job.
Mrs May has spoken to European leaders to express her "commitment to delivering the will of the British people to leave the European Union", according to a Downing Street spokesman.
In a series of congratulatory phone calls taken by Mrs May, the UK's second female prime minister spoke to German Chancellor Angela Merkel, French President Francois Hollande and Irish Taoiseach Enda Kenny.
"The prime minister explained that we would need some time to prepare for these negotiations and spoke of her hope that these could be conducted in a constructive and positive spirit," a Downing Street spokesman added.
Speaking outside Downing Street for the first time as prime minister on Wednesday Mrs May vowed to lead a government that works for all, not just the "privileged few", promising to give people who were "just managing" and "working around the clock" more control over their lives.
For an "ordinary working class family", she added, "life is much harder than many people in Westminster realise".
She highlighted the "precious bond" between England, Scotland, Wales and Northern Ireland and between "every one of us", and paid tribute to her predecessor David Cameron as "a great modern prime minister".