Sadiq Khan: Labour's choice for mayor
As he now seeks a mandate from five million Londoners, his personal and political journey will be scrutinised like never before.
Sadiq Khan has a back-story that may appeal to people who've never cast a vote in their lives.
He grew up on a south London housing estate, one of eight children, his father a bus driver. His children went to the same primary school as him. The Tooting constituency he represented since 2005 is where he's lived all his life.
In the second decade of the 21st Century some might argue the fact he is Muslim should pass unremarked. But his accession to City Hall would, for many, be a powerful statement of the city's diversity.
Some worry it may have the potential for division, but Khan has so far proved himself an inclusive campaigning force.
He's managed to be difficult to pigeonhole, occasional glimpses of radicalism disturbing the general picture of conformity which saw the human rights lawyer fit quite smoothly into the late New Labour model.
Is it sometimes a bit too smooth; is the calculation too obvious, ask some observers?
His victory in the Labour selection race trumps - for him - the campaign which won Ed Miliband the Labour leadership, in which Khan played a big part. The reward was senior roles as shadow lord chancellor and shadow justice secretary.
Some felt his association with the Miliband years would hamper his mayoral bid, but there was compensation in a reasonable result in London in May when the party gained seven seats.
Dame Tessa Jowell may have started as favourite, and was consistently ahead in the limited polling which was done.
But Khan - as shadow London minister - has spent the last few years closely involved in local election campaigns and getting his face seen around the capital's constituency groups.
He had the support of around half of London's Labour MPs and many senior figures in local government.
But victory appears to have been clinched because of the influence of the unions. Several endorsed him directly and he appears to have benefited from the Corbyn effect.
He came in for some flak from his rivals when he reversed his previous position and came out against expanding Heathrow Airport.
That is not his party's current position, but it seems to have been another careful calculation designed to neutralise the ace held by Zac Goldsmith, who it is assumed will line up against him in the race for City Hall.