New Prime Minister Theresa May has made Boris Johnson, the former London mayor who led the Brexit campaign, foreign secretary in her new government.
He replaces Philip Hammond, who becomes chancellor. Ex-Energy Secretary Amber Rudd is home secretary and Eurosceptic David Davis is the Brexit minister.
No 10 said ex-Chancellor George Osborne had resigned from the government.
On arriving at Downing Street, Mrs May vowed to lead a government that works for all not just the “privileged few”.
The UK’s second female prime minister promised to give people who were “just managing” and “working around the clock” more control over their lives.
Michael Fallon continues as defence secretary, and Liam Fox, who resigned as defence secretary in 2011, has a new role as international trade minister.
Mrs May has spoken of the need to reunite the Conservative Party after the EU referendum, in which she backed a Remain vote.
Her new line-up includes big jobs for prominent Leave campaigners Mr Johnson – who was initially tipped as the next prime minister after the Brexit vote – Mr Fox, and Mr Davis, whose job title is “secretary of state for exiting the European Union”.
On Twitter, Mr Osborne, who was chancellor throughout Mr Cameron’s tenure, said it had been a “privilege”, adding: “Others will judge – I hope I’ve left the economy in a better state than I found it.”
After returning from Buckingham Palace, where she was formally appointed as prime minister by the Queen, Mrs May made a speech from outside 10 Downing Street.
Her husband Philip was standing behind her as she highlighted the “precious bond” between England, Scotland, Wales and Northern Ireland and between “every one of us”.
“That means fighting against the burning injustice that if you’re born poor you will die on average nine years earlier than others,” she said.
For an “ordinary working class family”, she added, “Life is much harder than many people in Westminster realise.”
“When it comes to opportunity, we won’t entrench the advantages of the fortunate few, we will do everything we can to help anybody, whatever your background, to go as far as your talents will take you,” Mrs May said.
She also paid tribute to her predecessor, David Cameron, saying he had been a “great, modern prime minister”.