David Blunkett's life and political career has been one of the most colourful and controversial in recent British history. Here are the highlights:
Mr Blunkett's childhood has been described as almost Dickensian in its bleakness.
Born blind, he was packed off to a council boarding school at the age of four, against the wishes of his parents, who were only allowed to visit him once a month.
Then, when Mr Blunkett was 12, his father was killed in a horrific accident at work, falling into a vat of boiling water.
Mr Blunkett and his mother were left virtually penniless and fought a long battle for compensation from the Gas Board.
Through his own determination, Mr Blunkett won a place at Sheffield university, after taking O levels and then A levels at a succession of blind schools.
He was already a Labour councillor when he took his degree and became leader of Sheffield council 10 years later at the age of 33.
EARLY POLITICAL CAREER
The 1970s were the era of the hard left and Mr Blunkett's home patch was dubbed the "Socialist Republic of South Yorkshire".
As Sheffield council leader for seven years, Mr Blunkett courted controversy by allowing the red flag to be flown over the council's headquarters.
Mr Blunkett entered Parliament for Sheffield Brightside in 1987, after first contesting the Sheffield Hallam seat in 1974.
He chaired the Labour Party during the 1980s, gradually shedding his hard left sympathies and transforming himself into one of the leading voices calling for modernisation of the party, helping to pave the way for New Labour.
After shadowing the Conservative health and education ministers, he was handed the employment and education brief after Labour's landslide 1997 election victory.
Mr Blunkett's success as education secretary saw him promoted to home secretary after the 2001 election.
Despite his lack of legal training, it was a job he revelled in, although his original plans for it were blown off course by the terrorist attacks on 11 September.
Security and immigration now dominated and Mr Blunkett was not afraid to take on the legal establishment, dubbing those who stood in his way "airy-fairy libertarians".
It was not long before Mr Blunkett was being talked of as a future prime minister.
Mr Blunkett once confessed to missing out on the 1960s. He went to few parties during his student years.
So as a high profile home secretary with a punishing workload, few people begrudged him a taste of the high life - even when news of his relationship with a married women, glamorous magazine publisher Kimberly Quinn, began to emerge.
Mr Blunkett was divorced from his wife, and although he was close to his three sons, his home life was thought to be a lonely one.
But the affair impinged disastrously on his political career when it emerged a visa for Mrs Quinn's nanny had been fast-tracked by Mr Blunkett's department.
It also led to a custody battle over the child Mr Blunkett fathered with Mrs Quinn.
Mr Blunkett had little option but to quit the Cabinet, displaying his little-seen emotional side in a tearful resignation interview during which talked of his fondness for his young son, "that little lad".
Mr Blair made it clear that his friend and ally's return to the frontbench was virtually guaranteed.
Mr Blunkett's enthusiasm for Mr Blair's reform agenda was seen as vital to the prime minister's third term and it was only five months before he was brought back into Cabinet as work and pensions secretary.
His personal background was thought likely to give potentially unpopular pensions and welfare reform policies credibility - and Mr Blair was relying on his tough-talking style to drive the legislation through parliament.
But the fallout from his relationship with Ms Quinn, and the child he had fathered with her, continued to overshadow his career.
Newspaper stories of a friendship with a 29-year-old woman he had met in Mayfair night club Annabel's only added to the impression of recklessness.
The image of a Sheffield lad whose head had been turned by the bright lights of London, however inaccurate, was beginning to take hold in the public's mind - and was only exacerbated by a Channel 4 drama satirising the Quinn affair.
He was also increasingly isolated from his political colleagues, after criticising many of them in a book.
More than anything, Mr Blunkett - formerly seen as a safe pair of hands - was increasingly being seen as a minister unwilling to keep his head down and stay out of trouble.
His decision to resign over his brief directorship of a DNA testing company, effectively brings to an end his frontline political career.
But Mr Blunkett has overcome adversity before and few would bet that his extraordinary story is over yet.