It was as Tony Blair’s Labour culture secretary in the early noughties that she championed the capital’s eventually successful bid to host the games, in the face of Civil Service and Cabinet scepticism.
Though losing her Cabinet post in Gordon Brown’s 2007 reshuffle she remained Olympic minister and oversaw every stage of the games from initial bid to competition.
Ed Miliband, who was Labour leader during the games, said at the time she had left an “enormous” legacy and that the country owed her a “debt of gratitude”.
Tessa Jowell’s journey to Parliament was a long one. She first stood in a 1978 by-election in Ilford North on the Essex/London border, a seat now held by Labour’s Wes Streeting.
The former social worker lost to her Conservative rival, and was defeated again in the following year’s general election.
Ilford North would not fall to Labour until 1997, by which time Ms Jowell had been an MP for five years in the south London Dulwich and West Norwood constituency.
In 1997 she was one of the 101 female Labour MPs on the Government benches following the party’s landslide victory who were dubbed, in less self-aware times, the “Blair Babes”.
A succession of ministerial jobs followed, including employment minister and minister for women, before she joined the Cabinet as culture secretary in 2001.
Here she took on the job of convincing unsure colleagues about the merits of hosting the Olympics in 2012. London finally won the vote in July 2005.
Her backing for the games was not unquestioning however. In 2008, after the Great Recession struck, costing thousands of jobs, she said: “Had we known what we know now, would we have bid for the Olympics? Almost certainly not.”
In 2012 she was made Dame Tessa Jowell in the Birthday Honours for political and charitable services, which were partly in recognition of her work on the Olympics.
Three years later, after stepping down from the Commons at the 2015 general election, she was made Baroness Jowell of Brixton.
She later stood to be Labour’s candidate for mayor of London in 2016 but lost out to Sadiq Khan.
Her career was not without controversy.
She split from her lawyer husband David Mills in 2006 when she admitted being unaware he had paid off part of their mortgage with £350,000 at the centre of a bribery case involving former Italian prime minister Silvio Berlusconi.
Mr Mills was charged along with Mr Berlusconi with corruption in Milan and was convicted in his absence in February 2009, before being acquitted by the Italian Supreme Court under Italy’s statute of limitations a year later.
The couple parted after it was said to be damaging Dame Tessa’s career, but they were later reconciled.
Mr Mills accompanied her, along with their children Jess and Matthew, to Buckingham Palace when she was invested with her damehood in January 2013.
The speed of her late physical decline was dramatic.
On May 24 2017 she had two seizures in a taxi as she made her way to a talk in east London.
Two days later she was told she was suffering from a rare type of brain tumour, glioblastoma multiforme (GBM).
Her last few months saw her campaign for more cancer treatments to be made available through the NHS.
It included an emotional January 2018 speech in the Lords in which she called for more opportunities for “adaptive trials” in which patients can undergo different treatments, and if one does not work they can immediately move on to the next.
She told peers: “In the end, what gives a life meaning is not only how it is lived, but how it draws to a close.
“I hope this debate will give hope to other cancer patients like me. So that we can live well with cancer, not just be dying of it.”