Tony Blair has handed over as Labour leader to Gordon Brown with both men heaping praise on each other. But their relationship has not always been so cordial. Here is a brief history of it.
JUNE 1983: BLAIR AND BROWN ENTER THE COMMONS
Tony Blair and Gordon Brown became MPs in the same year
Tony Blair and Gordon Brown first met as backbench MPs in 1983, when they were among the Commons intake following that year's general election.
The men shared an office, forming a relationship that would come to change the direction of the Labour party.
Mr Blair was seen by some colleagues as the more amiable of the pair - Mr Brown the more bookish.
MAY 1994: DEATH OF JOHN SMITH AND ON TO GRANITA
The death of Labour leader John Smith marked a turning point in the relationship between Mr Blair and Mr Brown.
As the home affairs spokesman, Mr Blair pushed for modernisation of the party and was favourite to win the leadership election, ahead of Mr Brown and other potential rivals.
On 31 May the pair famously met at Granita restaurant in Islington, where the then shadow chancellor is said to have agreed to step aside and give Mr Blair a clear run.
The other part of the deal, that Mr Blair would one day stand down in favour of the chancellor, has since filled countless newspaper inches and even made a TV drama. Mr Blair's supporters, however, say that no such deal was made.
In a landslide victory over John Prescott and Margaret Beckett, Tony Blair became Labour leader in July 1994.
MAY 1997 - 2003: PRIME MINISTER BLAIR
Although largely conducted behind closed doors, the supposed rivalry between the new prime minister and his chancellor quickly became a source of great interest.
The splits between the men are seldom seen in public
Public expressions of discord were left to their allies - like Peter Mandelson and Alistair Campbell for Mr Blair and Charlie Whelan for Mr Brown.
Relations appeared particularly strained when, in 1998, Mr Campbell reportedly described the chancellor as "psychologically flawed".
As Labour's term of office wore on, there were increasing reports of Mr Brown's irritation at the prime minister's refusal to name the date of his departure, and the splits between them widened to take in more fundamental issues.
The euro was one, with Mr Blair more keen - at least at first - to promote UK entry to the currency than his more cautious Treasury neighbour.
Another was the future of public services. Mr Blair's market-orientated approach was disliked by Mr Brown.
Clashes followed over key policies including the introduction of university top-up fees and foundation hospitals.
SEPTEMBER 2003: PACT SPECULATION RESURFACES
Coverage of the feud resurfaced when, in a tub-thumping conference speech, Mr Brown said Labour was "best when we are boldest, best when we are united, best when we are Labour".
The remarks were seen as a challenge to the prime minister's authority at a time when some delegates were looking for an alternative leader.
Mr Brown's 2003 speech sparked another round of speculation
Newspaper reports suggested relations between the two men remained difficult in the following months, with Mr Blair "snubbing" Mr Brown's request to join the party's ruling NEC.
Nevertheless, a new pact appeared to have been made by autumn 2003, with Brownites claiming Mr Blair would step down before the general election.
MAY 2004: SUCCESSION DEBATE UNDERWAY
Cabinet ministers were talking about their future should Tony Blair step down, Deputy Prime Minister John Prescott said in May 2004.
Speaking of "moving plates" and people "repositioning themselves", he said there was speculation about Mr Blair's position.
He told the Times that there had been a "pretty serious breakdown of relations" between the men early in the life of the Labour government, but that things had since improved.
JANUARY 2005: 'NOTHING YOU COULD SAY'
While recovering from a reoccurrence of his heart problem in September 2004, Mr Blair said he said he would serve a "full third term" before stepping down.
The decision - according to a book by the BBC's business editor Robert Peston - was followed by Mr Brown telling the prime minister: "There is nothing that you could say to me now that I could ever believe."
Mr Brown's camp subsequently distanced itself from the comment, while Mr Blair said he could not recall the chancellor saying it.
MAY 2005: ELECTION DOUBLE ACT
Reports that Mr Blair and Mr Brown were barely speaking surfaced in the run-up to the 2005 election.
The 2005 election saw a united front - and ice creams
Initially, the chancellor was not at the centre of campaign planning, but as it drew closer he was increasingly involved.
At one point, the prime minister bought the chancellor an ice cream as the cameras clicked away during an appearance together.
Following Labour's election visit rumours resurfaced, with Mr Brown's absence at the G8 summit in Gleneagles duly noted. It was reported that one of the chancellor's allies described it as being "like Hamlet without the Prince".
AUGUST 2006: TOWARDS A SUCCESSION CRISIS
Soon after returning from a Caribbean holiday, Mr Blair told a newspaper he would not give a date or timetable for leaving office at the Labour conference later in September.
It had the opposite of the intended effect as fresh speculation and allies' barracking broke out. There were reports of Labour MPs - including ministers - signing a letter or letters urging Mr Blair to go, and by the leak of an apparent "farewell tour" memo from prime ministerial advisors.
It talked of "opportunities and threats" that include Gordon Brown's reaction: "The more successful we are, the more it will agitate and possibly destabilise him. We need to consider how to deal with that".
A new level was reached on 6 September when there were reports of Mr Blair and Mr Brown having an "acrimonious meeting" over the succession issue, which was followed by the resignation of a junior minister and seven government aides who had urged Mr Blair to stand down.
Mr Blair, with evident reluctance, announced he would quit within a year.
But allies of the chancellor denied the resignations had been part of a coup plot by the Brown camp.
NOVEMBER 2006: THE BIG CLUNKING FIST
Speculation runs wild about a possible Blairite challenge for the leadership as Mr Blair's time in Downing Street starts to run out.
Possible "anyone-but-Gordon" candidates touted by the media - and it is suggested Mr Blair himself - include Home Secretary John Reid and Environment Secretary David Miliband.
Not surprisingly, the merest hint of an endorsement from Mr Blair - or even a recognition that he will one day be gone as prime minister - is seized upon.
The first example of this comes in the Commons, when Mr Blair is speaking about the next election. He says of Tory leader David Cameron: "However much he dances around the ring beforehand, he will come in reach of a big clunking fist and, you know what, he'll be out on his feet, carried out of the ring."
The "big clunking fist" in question is taken by most pundits to be Mr Brown, who is sat behind the prime minister, although, as was with other oblique references to the succession by Mr Blair, it could equally be applied to Mr Reid.
Mr Blair clearly meant the remark as a compliment but it was quickly adopted by the opposition to mock what they saw as Mr Brown's insensitive, macho style of politics.
MAY 2007: THE ENDORSEMENT
There is a sudden outbreak of mutual admiration as Mr Blair endorses the chancellor's candidacy for the party leadership, praising him as "an extraordinary and rare talent".
Mr Brown took care to mention his 'friend' Tony Blair
"As someone who has known him for over 20 years as a friend and a colleague, he can make a real difference to this country for the better and for the good.
"I wish him well and, as I say, I'm delighted to support him and endorse him fully," adds Mr Blair.
The fact that endorsement comes at the very last minute, when all possible heavyweight challengers to Mr Brown have fallen by the wayside, appears to have been forgotten as the pair speak warmly of their longstanding friendship.
Asked at his campaign launch why Mr Blair has waited so long to offer his unconditional support, Mr Brown tells reporters: "I am pleased that Tony Blair, who is my friend, has endorsed me this morning.
"It was always his intention to do so as he made his own decision about when he was to leave.
"Look, I have worked with Tony Blair for more than 20 years. We shared an office together, we grew up in politics together, we work well together."
JUNE 2007: THE HANDOVER
Tony Blair hands over the leadership of the Labour Party to Gordon Brown at a special party conference in Manchester.
The Sunday newspapers are full of fresh revelations about the two men's troubled relationship, with the Independent on Sunday publishing leaked documents suggesting Mr Blair planned to sack Mr Brown as chancellor after the 2005 election.
The confidential strategy papers, written by Mr Blair's "blue skies thinker," the former BBC Director General John Birt, suggested curbing the power of the Treasury.
But all of this appears to have been forgotten, as Mr Blair telling his final Cabinet meeting a few days earlier that Mr Brown has all the qualities to be an excellent prime minister.