The decision to use force led to profound controversy in relation to Iraq and became even more controversial when it was subsequently found that Iraq's programs to develop and produce chemical, biological and nuclear weapons had been dismantled.
There were many people who spoke out against the war, the public protested, alongside leading figures and politicians from the Labour, Conservative parties and the Liberal Democrats, who all voiced their opinion against a war that was not based on the correct intelligence and has since been recognized as such by Sir John Chilcot, who was critical of Tony Blair's government, which accepted flawed intelligence reports of Saddam Hussein's weapons of mass destruction.
The then-Prime Minister, Tony Blair, continued to fight the outspoken members of his party and went into battle with Former President of the US, George W Bush.
However, regardless of whether they were listened to or not, former MPs, Robin Cook and Charles Kennedy refused to give up.
The release of the Chilcot report saw vindication for both men who were demonized for standing up against the war, sadly neither lived to see the day.
Speaking in Parliament after Prime Minister's Questions on July 6, Labour leader, Jeremy Corbyn paid tribute to the late Cook, who resigned from the cabinet over the Iraq War in a speech to the Commons in March 2003.
"Iraq probably has no weapons of mass destruction in the commonly understood sense of the term — namely a credible device capable of being delivered against a strategic city target.
Cook later died of a heart attack while walking in the Scottish Highlands on 6 August 2005.
The then Liberal Democrat leader, Charles Kennedy, was key opponent of the Iraq war and spoke at anti-war rally in Hyde Park in February 2003 to further voice his resistance to what was by then an inevitable conflict.
Kennedy was condemned by The Sun newspaper and was compared to a spineless reptile.
"Our country has a principled and a responsible role to play on the world stage but to do so we have to pursue international justice through the United Nations and our government has got to take its people with them. It's patently failing and that is my message for you today. Thank you," Charles Kennedy said in his speech at Hyde Park.
He died at his home at the age of 55.
Both of these men finally received the vindication they so rightly deserved after the Chilcot report was released. They may never have got to see the outcome of their fight for justice, which saw them criticized and mocked. However they will be remembered within the Iraq legacy as two fierce opponents of the war, who fought for peace and will be known as two leaders who stood on the right side of history.