Jeremy Corbyn has been elected as the new Labour Party leader, making him the leader of the UK's official opposition. Here's a guide to him and his victory.
What just happened?
A 66-year-old left-wing MP, Jeremy Corbyn, has won the leadership of the UK's official opposition.
It was a landslide win - he got 59.5% of the vote. For context, former Prime Minister Tony Blair got 57% of the vote when he was elected Labour leader in 1994.
Bookmakers in particular have had their feathers ruffled - he began the contest in May as a 200 to 1 outsider. In fact, his support was so low, he made it on to the ballot only when some MPs who did not agree with his policies nominated him to "broaden the debate".
Yet Labour supporters warmed to his anti-austerity message and he seems to have captured their imaginations. His victory was also helped by a 2014 change in Labour leadership rules, which allowed tens of thousands of non-party members to vote for a fee of £3 .
Read more: How Mr Corbyn won it
Remind me again, who is he?
Born in a market town in Wiltshire, in the west of England, his father was an engineer and his mother was a maths teacher.
He spent two years working in a voluntary service programme in Jamaica before leaving the North London Polytechnic without a degree.
He was active in Labour politics, firstly in Shropshire and then in London, where he was a local councillor for nearly a decade.
His only paid job outside politics was working for two trade unions, the National Union of Public Employees and the National Union of Tailors and Garment Workers.
He was first elected to Parliament in 1983, when Margaret Thatcher was prime minister.
He has been MP for the London constituency of Islington North for 32 years, being re-elected seven times.
Compared with many other candidates, a lot of press attention focused on his appearance - with reports suggesting he was given a (very gentle) makeover in recent weeks.
Read more: The Jeremy Corbyn Story
So why is his win significant?
Rewind a few years.
After election defeats in the 1980s, Labour ditched a number of far-left policies and moved more towards the centre - a move that Mr Corbyn opposed.
For the Labour Party, it worked. Under Tony Blair and Gordon Brown, the party stayed in power for 13 years.
His election as Labour leader reflects a pattern in other European countries, such as Greece and Spain, of a move towards the far left.
Having said that, the next UK election will be in 2020 and the Conservative Party has a majority in parliament. It may be a while before we see whether there is a wider Corbyn Effect.
What do people make of his win?
Mr Corbyn marked it by visiting a pub with young supporters, although he doesn't drink, and later attended a march in solidarity with refugees.
Elsewhere, it's fair to say there was a range of opinions. On one hand, his victory was called "the greatest against all-odds victory in British political history",
On the other, it was called "an act of political stupidity unparalleled since Caligula appointed his horse to the Roman senate".
One thing is certain - it has led to plenty of people online pointing out how much Mr Corbyn resembles a particular Star Wars character.
What does he believe in?
As a democratic socialist, he believes in:
- higher taxation for the wealthiest
- greater public ownership, with the railways and utilities earmarked for renationalisation
- an end to private involvement in the health service
- a new free national education service
- an agenda of "growth not austerity"
He has pledged to oppose spending cuts and said he would use the Bank of England to pump billions into the economy to boost infrastructure and manufacturing.
Read more: What is Corbyn's programme for government?
What about his free time?
As a full-time advocate for peace and human rights, political campaigning has been his lifetime's work.
But this is what we do know about his interests: according to the Financial Times, "he loves making jam with fruit grown on his allotment, belongs to the All Party Parliamentary Group for Cheese and is a borderline trainspotter".
He is a vegetarian and a keen cyclist - he does not own a car - as well as being a supporter of Arsenal football club.
He has been married three times, most recently earlier this year. He has three sons, one of whom worked for his leadership campaign, while his brother Piers is an astrophysicist and weather forecaster.
Oh, and he loves hummus.
What's his view of the world?
He has vowed to stop the UK entering any more "illegal wars", saying he cannot conceive of any situation in which he would deploy British troops abroad.
A fierce opponent of the 2003 Iraq War, he helped found the Stop the War Coalition. A long-time campaigner for unilateral nuclear disarmament, he has called for Trident, the UK's nuclear weapons system, to be scrapped.
He also wants reform of Nato, saying it has expanded too aggressively.
On Europe, he has indicated he would campaign to keep the UK in the EU but has criticised Brussels for being too pro-business.
He has, though, been criticised for the company he keeps, having once invited representatives of Hamas and Hezbollah to Parliament.
Has he ever worked in government?
Nope. He has never been offered a job by any Labour leader over the past 30 years.
In fact, he has spent a lot of his time opposing them - he was the most rebellious Labour MP between 1997 and 2010 and has voted against his party more than 500 times.