MPs have overwhelmingly backed UK air strikes against so-called Islamic State in Syria, by 397 votes to 223, after an impassioned 10-hour Commons debate.
A total of 66 Labour MPs sided with the government as David Cameron secured a larger than expected Commons majority.
The PM said they had "taken the right decision to keep the country safe".
Labour leader Jeremy Corbyn had said the case for war did "not stack up" but shadow foreign secretary Hilary Benn had urged MPs to "confront this evil".
Welcoming the Commons result, Foreign Secretary Philip Hammond said Britain was "safer because of the actions taken by MPs today".
He added: "Military strikes alone won't help Syria, won't keep us safe from Daesh. But this multi-strand approach will."
The UK has been bombing IS (also known as Isis and Daesh) in Iraq since last year and the vast majority of Conservative MPs supported allowing UK air strikes in Syria as well, with just seven - far fewer than expected - voting against.
The SNP, all of whose 54 MPs opposed military action, said it was disappointed and feared the outcome would lead "to Iraq and Libya all over again".
By Laura Kuenssberg, BBC political editor
David Cameron has achieved his long-held goal.
Intervening against the extremist forces who call themselves the Islamic State in Syria - it seemed impossible less than a month ago. But in the weeks since the Paris attacks, the prospect of extending bombing strikes into Syria from Iraq has taken on a reluctant inevitability.
But for the prime minister, with this, his third big foreign intervention - Libya, Iraq, now Syria - pulling together a wider plan to achieve real peace is a far more complex task, one he acknowledges the UK cannot complete on its own.
'Public opposition growing'
Mr Corbyn had argued that air strikes would "almost inevitably" result in the deaths of innocent people - but his party was split, with senior Labour figures - including 11 members of the shadow cabinet - voting with the government after they were given a free vote.
The 66 Labour MPs who backed military action was equivalent to 29% of the parliamentary party.
Reacting to the vote, aides to Mr Corbyn said a majority of the parliamentary party and the shadow cabinet had backed his position and the leader's authority had been "enhanced".
Shadow international development secretary Diane Abbott said Mr Corbyn was more in line with the public than the prime minister, telling the BBC that "very soon public opinion will tire of Cameron's war".
But the United States, which along with France, Russia and other countries are already conducting missions in Syria, welcomed the vote, saying "it looks forward to having UK forces flying with the coalition over Syria".
Anti-war protesters staged a demonstration outside Parliament as MPs debated the issue, with one woman crawling under a lorry and refusing to move. She is reported to have been arrested.
Mr Cameron had opened the debate insisting Britain must decide whether it wanted to take on the "evil" of IS, which he said should be referred to as Daesh, in Syria or "wait for them to attack us".
He refused to apologise for saying opponents of military action were "terrorist sympathisers" but said there was "honour" in voting for or against military action.
He also defended his claim that there were 70,000 moderate opposition fighters in Syria, saying it was the estimate of the Joint Intelligence Committee - the UK's senior intelligence body.
But Mr Corbyn accused the PM of rushing the vote because he understood "public opposition to his ill thought-out rush to war is growing".
And he disputed Mr Cameron's claim about ground troops, saying it was "quite clear there are no such forces" and only extremists would take advantage of the strikes against IS.
'The threat is now'
However, as the debate drew to a close Mr Benn was applauded by MPs from across the House, particularly on the Conservative benches, when he urged his own side to "confront this evil" posed by Islamic State, who he said "held our democracy in contempt".
In an impassioned speech, Mr Benn said the international community was "faced by fascists and what we know about fascists is that they must be defeated". While there were "rarely perfect circumstances to deploy military forces", he said "the threat is now" and the UK must rise to the challenge.
Former Cabinet ministers Alan Johnson, Yvette Cooper and Margaret Beckett also spoke in favour of military action while deputy leader Tom Watson and former acting leader Harriet Harman also voted with the government.
But former leader Ed Miliband was among the 153 Labour MPs to vote against.
Full list: The Labour MPs who supported military action
- Heidi Alexander, Ian Austin, Adrian Bailey, Kevin Barron, Margaret Beckett, Hilary Benn, Luciana Berger, Tom Blenkinsop, Ben Bradshaw, Chris Bryant, Alan Campbell, Jenny Chapman, Vernon Coaker, Ann Coffey, Yvette Cooper, Neil Coyle, Mary Creagh, Stella Creasy,
- Simon Danczuk, Wayne David, Gloria De Piero, Stephen Doughty, Jim Dowd, Michael Dugher, Angela Eagle, Maria Eagle, Louise Ellman, Frank Field, Jim Fitzpatrick
- Colleen Fletcher, Caroline Flint, Harriet Harman, Margaret Hodge, George Howarth, Tristram Hunt, Dan Jarvis, Alan Johnson, Graham Jones, Helen Jones, Kevan Jones, Susan Elan Jones, Liz Kendall, Dr Peter Kyle, Chris Leslie, Holly Lynch, Siobhain McDonagh,
- Pat McFadden, Conor McGinn, Alison McGovern, Bridget Phillipson, Jamie Reed, Emma Reynolds, Geoffrey Robinson, Joan Ryan, Lucy Powell, Ruth Smeeth, Angela Smith, John Spellar, Gisela Stuart
- Gareth Thomas, Anna Turley, Chuka Umunna, Keith Vaz, Tom Watson, Phil Wilson and John Woodcock