Video report by ITV News Political Editor Robert Peston
Theresa May moved into Number 10 on a momentous day in British politics, which saw David Cameron and his family leave Downing Street for the final time after six years in office.
Here's a look at how the today unfolded in pictures:
The House of Commons was packed for David Cameron's last Prime Minister's Questions. Credit: PA
David Cameron's final PMQs before resigning as prime minister. Credit: PA
David Cameron and his wife Samantha return to Downing Street after his last PMQs. Credit: PA
David Cameron makes his final speech as prime minister, flanked by his family. Credit: PA
A huge media scrum watched David Cameron's last speech in Downing Street. Credit: PA
The Camerons wave on the steps of Number 10. Credit: PA
David Cameron and his family embrace as they leave Downing Street for the last time. Credit: PA
The Cameron family leave Downing Street for the final time. Credit: PA
David Cameron arrives at Buckingham Palace to hand in his resignation. Credit: may
Theresa May arrives at Buckingham Palace. Credit: PA
The Queen welcomes Theresa May at the start of an audience in Buckingham Palace. Credit: PA
Theresa May chats with The Queen at Buckingham Palace. Credit: PA
Theresa May and her husband Philip arrive in Downing Street. Credit: PA
Theresa May makes her first speech as prime minister, flanked by her husband Philip. Credit: PA
Theresa May and her husband Philip wave to the cameras. Credit: PA
Theresa May is applauded by staff as she walks into 10 Downing Street. Credit: PA