From a figure of fun among the Conservatives to a saviour of the union principles they stand for, Gordon Brown's political life has been rejuvenated by the referendum campaign.

The Labour former prime minister appeared destined for a quiet life on the back benches of Westminster - alongside his charitable projects - following his withdrawal from frontline politics after losing power at the 2010 general election.

He remained as an MP for Kirkcaldy and Cowdenbeath but his appearances in the House of Commons were occasional - so much so that they attracted a few more onlookers at traditionally quieter times in Parliament.

For the Tories, and other political observers, Mr Brown was also a man who accidentally claimed in 2008 that the then-Labour government had "saved the world". He meant to say the banks.

But it was a slip of the tongue during a session of prime minister's questions which sent then-opposition leader David Cameron and his Tory Party into hysterics, and became a reference point for his less than smooth period, particularly presentation-wise, in office at No 10.

But as the referendum campaign neared its climax, Mr Brown emerged from the shadows to play an increasingly prominent role in the No camp.

He announced a new fast-track timetable for further devolution to Scotland, pledging that work would begin the day after the referendum in the event of a No vote.

And the former prime minister received widespread praise from fellow No campaigners, including those considered political opponents, as he pleaded with undecided voters to reject the "risks" of independence.

Such was the reaction to the speech that Mr Brown was even mocked up as Flash Gordon on Twitter.

Now with the campaign at an end, the words of Prince Vultan are left ringing in the ears: "Gordon's alive!"

Meanwhile, the chancellor who brought the UK's troubled banks back from the brink can claim credit for saving the union.

Alistair Darling took the reins of the No campaign in June 2012, when support for independence stood at around 35%.

While that support rose rapidly in the final stages of the two-year debate, causing concern for Mr Darling and his unionist colleagues, the increase was not enough to secure a Yes verdict.

And while Mr Darling, as campaign leader, can claim to have delivered the No vote, many will argue he was forced to take a lesser role in the final days of the campaign.

For a long time the Labour MP stood front and centre at the helm of the fight to keep Scotland in the UK, taking on Alex Salmond in the two live televised leaders debates.

Mr Darling was broadly judged to have won the first of those verbal tussles, but his performance was said to have slipped in the second, with the First Minister was hailed the victor.

Often described as taking a "bank manager" approach, Mr Darling sought to focus on the "uncertainties" of independence, questioning what a Yes vote would mean for currency, pensions, jobs and mortgages.

Despite praise from his political colleagues for continuing to plough the furrow of such uncertainties, it was his Labour colleague and former Prime Minister Gordon Brown who came to the forefront in the last days before the crucial vote.

A prominent name in British politics for many years, Mr Darling had stepped away from the frontline following his party's election defeat in 2010.

But the September 18 independence referendum returned him to the thick of political life.

He had initially insisted he was not interested in leading the pro-Union campaign, declaring he was ''too busy as a Westminster MP'' in January 2012.

Mr Darling added: ''This campaign has to be run in Scotland.''

Despite that, the man who served both Tony Blair and Gordon Brown in government became the leader of the cross-party campaign for a No vote.

''I thought that unless there was a clear voice for those of us who believe in the United Kingdom, and that Scotland is better off in the United Kingdom, then we would lose it by default,'' he later told the Independent.

At the campaign launch in Edinburgh in June 2012, Mr Darling, flanked by leading Tory and Liberal Democrat politicians, warned right then that the choice facing voters is ''irrevocable''.

Mr Darling said: ''If we decide to leave the United Kingdom there is no way back. We can't give our children a one-way ticket to a deeply uncertain future.''

Born in London, but proudly Scottish, he is himself an example of ties that exist between Scotland and England.

He studied law at Aberdeen University, going on to become an advocate in 1984 - two years after he was elected to the former Lothian Regional Council.

He was elected to the House of Commons in the 1987 general election. But while he won his Edinburgh Central constituency, Labour failed to oust Margaret Thatcher from Downing Street, and he spent his first 10 years as an MP in opposition.

In 1997 Tony Blair's New Labour swept to power in a landslide victory, with Mr Darling joining the Government, initially as Chief Secretary to the Treasury.

He is one of only three people to remain in the cabinet between then and 2010, when Labour were defeated - Gordon Brown and Jack Straw are the others - and over this period he held a variety of roles.

He served as transport secretary, Scottish secretary and trade secretary, before being appointed chancellor when Gordon Brown took over as prime minister in 2007.

The following year, in an interview with the Guardian, he warned that the economic times Britain and the rest of the world were facing were ''arguably the worst they've been in 60 years''.

He later claimed that remark resulted in the ''forces of hell'' being unleashed, with allies of Mr Brown briefing against him.

But in his memoirs, titled Back From The Brink, Mr Darling said his prediction had proved to be ''fairly accurate''.

He was the man at the helm of the nation's finances when the crisis hit.

''I don't believe in panicking before it's absolutely necessary, but I came close to considering it on the morning of October 7 2008,'' he said.

He described how then Royal Bank of Scotland chairman Tom McKillop told him over the phone that the bank could keep going for ''a couple of hours maybe''.

Mr Darling recalled he felt a ''deep chill in my stomach'' before stepping in to keep the bank afloat.

''We would stand behind the Bank, even if it meant using every last penny we had,'' he decided.

''If RBS closed its doors, the banking system would freeze, not just in the UK but around the globe.''

In his campaign to keep the United Kingdom together, he questioned whether an independent Scotland would have been able to step in and act in such a way.

Such concerns - along with repeated questions over currency plans and the future of Scotland's economy - fuelled accusations from Better Together's rivals that it was running a "negative" campaign, a tag that Mr Darling and his colleagues struggled to shake off.

Nonetheless, such concerns - and Mr Darling's message that "if you don't know, vote No" held sway with the Scottish electorate.