The new leader of Britain's Labour Party, Jeremy Corbyn, has promised to lead a Labour fightback after its dismal showing in May's general election.
The 66-year-old got almost 60 percent of more than 400,000 votes cast, trouncing three rivals.
A parliamentary veteran of 32 years, who has many times in the past voted against his own party - notably against the war in Iraq - Mr Corbyn immediately faced an exodus of shadow cabinet members.
The Conservative Prime Minister, David Cameron, has portrayed him as a threat to both economic and domestic security.
And the former Labour prime minister, Tony Blair, has said the party was "walking eyes shut, arms outstretched over the cliff's edge".
However senior figures, including Ed Miliband, who abruptly quit as leader after the election, urged the party's MPs to get behind him.
Mr Corbyn was a 200 to 1 outsider when the three-month leadership contest began but he swept to victory on a wave of enthusiasm for his anti-austerity message.
He also promised to scrap Britain's nuclear weapons and re-nationalise the railways and major utilities such as energy companies.
The result is being seen as game changing for the UK's main opposition party.
The left-winger, who has spent his entire parliamentary career in the Commons on the backbenches, promised to fight for a more tolerant and inclusive Britain - and to tackle "grotesque levels of inequality in our society".
"I say thank you in advance to us all working together to achieve great victories not just electorally for Labour but emotionally for the whole of our society - to show we don't have to be unequal, it doesn't have to be unfair, poverty isn't inevitable."
As well as inequality at home, Mr Corbyn's acceptance speech focused on the refugee crisis in Europe.
His first act as leader was to attend a "refugees welcome here" rally, joining tens of thousands of people marching through central London in support of the rights of refugees.
Authentic voice - Little
The leader of the New Zealand Labour Party, Andrew Little, said Jeremy Corbyn had an authentic voice and that is why people voted for him.
Mr Little said Mr Corbyn's campaign reached out to those who felt excluded from the political process.
"Jeremy Corbyn spoke to a part of the constituency at the sharp end of austerity and other major cutbacks that clearly feels left out and hasn't had a voice. He's given them a voice and he's won a lot of popular support for that."
Mr Little said Mr Corbyn's campaign was amazing and reached out to those who felt excluded from the mainstream political process.
He said there would be a lot of hard work ahead to unite the caucus of the British Labour Party.
Mr Corbyn gained 251,417, or 59 percent, of first preference votes; 40 percent more than his nearest rival Mr Burnham, who got 19 percent.
Ms Cooper was third on 17 percent and Ms Kendall a distant fourth with 4.5 percent.
A total of 422,664 cast a vote - a turnout of 76 percent. Mr Corbyn was backed by few Labour MPs but he came way ahead of his rivals among party members, trade unionists and those who signed up for to take part for £3.
The three-month campaign saw a fight over the party's future direction.
Mr Corbyn - Labour's MP for Islington North for 32 years - has a long history of voting against his own party.
His agenda has included increasing government investment though money-printing and re-nationalising parts of the economy.
Senior figures within Labour have said having him as leader would leave their party unelectable.
In his acceptance speech, Mr Corbyn said the leadership campaign "showed our party and our movement, passionate, democratic, diverse, united and absolutely determined in our quest for a decent and better society that is possible for all".
He paid tribute to his three defeated rivals and promised to fight for a more tolerant and inclusive Britain - and to tackle "grotesque levels of inequality in our society".
He also made clear that his first day in Parliament as leader would see him oppose the government's efforts "to shackle unions in the Trade Union Bill which they are bringing forward on Monday".
Shadow health minister Jamie Reed, who has been an outspoken critic of Mr Corbyn, announced his resignation from the Labour front bench within seconds of Mr Corbyn's victory.
Mr Miliband resigned as the party's leader in the aftermath of the general election in May, in which the Conservatives won an overall majority.
- BBC / RNZ