Theresa May has called it "an honour and a privilege" to be the new Tory leader, as she thanked staff at the Conservative HQ in London.
She paid tribute to the man she will shortly replace as prime minister, saying David Cameron had been "a superb leader of our party and a superb prime minister".
She also stated that "when Labour prospers the country suffers", calling for a big win in the general election in four years time to "make sure they don't prosper".
What sort of a person is Theresa May? ITV News Security Editor Rohit Kachroo speaks to some of the people she fought for and against.
We will have the new occupants of the big cabinet posts in Theresa May's government announced tomorrow, I am told.
Find out how the likes of house prices, employment and migration levels and petrol prices compare with when Mr Cameron entered Number 10.