Winners and losers in Chilcot's devastating Iraq War report.
Mr Blair voiced "more sorrow, regret and apology than you may ever know or can believe" for his role in the invasion of Iraq. Following the publication of the Chilcot Report, the former Sedgefield MP said the decision to remove Saddam Hussein was the "hardest, most momentous, most agonising" of his 10 years in office.
"For that decision I accept full responsibility, without exception, without excuse," he told a news conference, his voice near breaking.
"For all of this I express more sorrow, regret and apology than you may ever know or can believe."
Here, we look at who the winners and losers are in the devastating document.
Sir John Chilcot - winner First, the author himself. Many feared the worst as the publication date for the report kept being put back and minds strayed to the Hutton Inquiry of 2003, called by the Tony Blair Government into the death of weapons inspector Dr David Kelly.
A BBC report claimed the Government had "sexed up" the intelligence it presented to the public in 2003 to justify the war. A row erupted between the Government and the BBC and Kelly was outed as the BBC's source.
Described as a pawn in the game, he was later found dead. To the astonishment of many, the Government was largely absolved of blame. However the Chilcot Report didn't become Hutton II and within its limits delivered a devastating verdict on Blair.
Tony Blair - loser If this is a whitewash, you can only wonder what sort of kicking the former Prime Minister would have received from the unvarnished truth. While Chilcot would not say whether he thought the war was illegal, he came pretty close to it. And the conclusions to be drawn from the report is of Blair with US President George W Bush "all the way" on invasion, ignoring or overlooking his colleagues in the Cabinet, the people of Britain who had protested in vast numbers against a war whilst ploughing ahead without the backing of NATO, the UN Security council or the EU.
Blair said the report "should lay to rest allegations of bad faith, lies or deceit". Some might wonder if he was reading the report, or re-reading his autobiography.
Jack Straw - loser Signed up to plans for an invasion in Iraq, despite fearing there could be "a long and unsuccessful war", the Chilcot Report found.
The report said the then-Foreign Secretary raised the question in response to a briefing in March 2003 of what would happen in the event of a protracted conflict, but"Mr Straw's question was not put to officials and there is no indication that it was considered further".
It also criticises Straw's role in the deeply flawed process of preparing for post-crisis Iraq, with the UK failing to win over Washington to its preferred plan for the UN to take the lead.
Alastair Campbell - winner Alastair Campbell, Tony Blair's Director of Communications, was cleared by Chilcot of the often-repeated accusation that he 'sexed up' an intelligence dossier that was presented to Parliament before the Iraq War.
"There is no evidence that intelligence was improperly included in the dossier or that No 10 improperly influenced the text," the report concluded.
Lord Goldsmith - loser The Attorney General at the time. While Chilcot does not pass judgment on whether the war was legal, the report says the way the legal basis was dealt with before the March 20 invasion was far from satisfactory. Chilcot said Goldsmith should have given written advice. Also, Goldsmith told Blair that war without a second UN resolution would be illegal, only to change his mind after a trip to Washington in March 2003 and meetings with Bush administration legal officials.
Robin Cook - winner Chilcot vindicated the judgment of the late Robin Cook, who resigned from the cabinet in March 2003 in protest over what he saw as the rush towards military action. While criticising the conclusions Blair and his inner circle drew from contemporary intelligence reports about the threat posed by Iraq, the Chilcot report said: "As Mr Cook's resignation statement on 17 March made clear, it was possible for a minister to draw different conclusions from the same information."
The Ministry of Defence - loser The report highlighted how the British forces lacked essential equipment such as armoured patrol vehicles and helicopters - and yet nobody at the Ministry of Defence appeared to be taking responsibility for the problems.
The MOD planned the invasion in a rush and was slow to react to the security threats on the ground, particularly the use of improvised explosive devices (IEDs) that killed so many troops, the report says.
But instead of quickly addressing serious equipment shortfalls such as the use of poorly protected Snatch Land Rovers when the conflict began, the MOD allowed delays to develop that "should not have been tolerated".
Geoff Hoon - winner Seen as a bit of Blair 'yes man' during his time as Defence Secretary, Hoon emerged from the report as a restraining influence on Blair in the year before the invasion of Iraq.
Hoon attempted, for example, to secure greater UK involvement in planning for the conflict and its aftermath, but to no avail.