The youngest commissioner this century, he has established a reputation as a reformer during his period in charge of 26,000 officers, the largest force in the country.
But his career has been beset by controversy, particularly over racially sensitive cases. It was during his stewardship that Joy Gardner, an illegal Jamaican immigrant, died of asphyxiation during a raid by officers seeking to deport her in 1993.
Two years later, there were riots in Brixton after Wayne Douglas died in a police station cell. Sir Paul also sparked public outrage when he stated in 1995 that the majority of muggers in London were black.
More recently, the Met has been criticised not only over the Stephen Lawrence case, but also for its investigation into the murder of the black musician Michael Menson. The case was so badly handled that his death was treated as suicide for a year.
Sir Paul, who grew up in a council house in Bournemouth, was an apprentice printer before joining the Met. He often expresses pride about the fact that he started on the same day in 1967 as Norwell Robert, the force's first black officer.
His own career took him on to the streets of the East End of London as a young beat officer. Marked out early as a high-flyer, he won a scholarship to St Peter's College, Oxford, where he took an honours degree in jurisprudence.
On his return to London, he joined Scotland Yard's community relations branch and became staff officer to Sir Kenneth Newman, who was then the commissioner.
Sir Paul's first big break came in 1988, when he was appointed Deputy Assistant Commissioner in charge of west London, with responsibility for policing the Notting Hill Carnival. He managed to rid the carnival of the violence that had marred it during the Eighties.
After four years as Chief Constable of the Kent force, where he introduced performance targets, he returned to the Met as Commissioner.
In the six years since he took over, crime figures have fallen to a 10- year low. He has also launched a crusade against corrupt officers, setting up a special squad of detectives dedicated to rooting out dishonesty.
Sir Paul, who is married and lives in Kent, has a reputation as something of a puritan. One of his first actions after becoming Commissioner was to convert the notorious "Tank" bar in the Scotland Yard basement - the watering hole for generations of detectives - into a fitness centre.
Even his critics say that his reforming instincts are sincere and that his weaknesses relate to leadership rather than attitude.
Despite the battering that the force has received over the Lawrence case, Sir Paul is still regarded as one of the Met's brightest and best. But, short of a miracle, he seems unlikely to survive the next fortnight.Reuse content