Sadiq Khan began his ceremonial duties as the new mayor of London in triumphant style - less than 12 hours after he was officially confirmed in the role.
The Labour MP was greeted warmly by actor Sir Ian McKellen as he strolled into Southwark Cathedral for his signing-in ceremony on Saturday morning. Khan was then given an impromptu standing ovation and received rapturous applause as he entered the packed cathedral.
Khan received a second sustained burst of applause and loud whooping when he introduced himself with: "My name is Sadiq Khan, I'm the mayor of London." Dean of Southwark Andrew Nunn told the congregation Khan's victory brought a "carnival atmosphere" to the sacred building.
During a brief speech, the human rights lawyer-turned-politician brought laughter from the floor as, in a nod to a much-referenced and parodied theme of his election campaign, he said: "Some of you don't know, but I grew up on a council estate." He repeated his vows to be a "mayor for all Londoners" during the short, multi-faith service.
He said: "I can't believe the last 24 hours. I want to start my mayoralty as I intend to go on. I want this to be the most transparent, honest and accessible administration London has ever seen." He added that his "burning ambition" was for people all across the capital to have the same opportunities he enjoyed.
While Jeremy Corbyn was the one to lead congratulations on Twitter, he was notably absent from the formal signing-in ceremony.
But former Labour leader and close ally Ed Miliband was there along with campaigner Baroness Doreen Lawrence, mother of murdered black teenager Stephen.
Baroness Lawrence said: "This really is a glorious day. I never imagined in my lifetime I could have a mayor of London from an ethnic minority."