After a stunning election night for the Tories, the Prime Minister paid generous tribute to his defeated rivals Ed Miliband and Nick Clegg who both announced that they would be quitting as leaders of their parties.
Winning the final seat to declare, St Ives, put the Conservatives on 331 seats giving the party a majority of 12.
Following an audience with the Queen at Buckingham Palace to confirm his second term in office, Mr Cameron returned to Downing Street with a pledge to restore unity to the country after a bruising five week campaign.
Speaking on the steps of No 10, Mr Cameron - who had repeatedly warned of the dangers of a Labour government propped up by the votes of the SNP - said he would press ahead with the promised further devolution to Scotland “as fast as I can”.
“As we conduct this vital work we must ensure that we bring our country together. We will govern as a party of one nation, one United Kingdom,” he said.
“That means ensuring this recovery reaches all parts of our country from north to south, from east to west, and indeed it means rebalancing our economy, building that northern powerhouse.”
This afternoon, Mr Cameron began appointing Cabinet Ministers beginning with the return of George Osborne to the Treasury. He will also carry the title of First Secretary of State, effectively making him the deputy prime miniser.
It was also confirmed Theresa May will continue as Home Secretary, Philip Hammond will remain as Foreign Secretary and Michael Fallon will retain the post of Defence Secretary.
Ed Miliband’s departure as Labour leader became inevitable after a night in which Labour was blown away north of the border by the Scottish Nationalists while failing to take any seats from the Conservatives.
Shadow chancellor Ed Balls, shadow foreign secretary Douglas Alexander and Scottish Labour leader Jim Murphy were among the high profile victims in a result which has shaken the party to its core.
Mr Clegg also had little choice but to quit after the Lib Dems’ tally of MPs was reduced from 56 to a rump of just eight, with Business Secretary Vince Cable, Treasury Chief Secretary Danny Alexander, and Energy Secretary Ed Davey among the fallers.
While Mr Clegg acknowledged that the Lib Dems had paid the price for five years in coalition with the Tories, he said the history books would judge their time in government “kindly”.
And he warned that the UK was at a “very perilous point” where the politics of grievance and fear risked driving the country apart.
“It is no exaggeration to say that, in the absence of strong and statesmanlike leadership, Britain’s place in Europe and the world and the continued existence of our United Kingdom itself is now in grave jeopardy,” he said.
Meanwhile, Nigel Farage resigned as Ukip leader after finishing second in Thanet South, telling activists “I’m a man of my word” after promising defeat would force him to quit.
But Mr Farage raised the prospect he would consider running to return to the job after a summer off when the contest is held in September.