David Cameron said being prime minister was "the greatest honour of my life" and paid tribute to the civil service as he left 10 Downing Street for the last time.
With his wife Samantha and their three children by his side, the outgoing Tory leader delivered an emotional address before going to Buckingham Palace to deliver his resignation to the Queen.
Cameron said Britain "is much stronger" than it was when he first became Prime Minister in 2010 – highlighting his government's efforts to improve the economy, as well as flagship policies such as the national living wage, reforms to the adoption system and the legalisation of gay marriage.
"It has been the greatest honour of my life to serve our country as prime minister over these last six years and to serve as leader of my party for almost 11 years," he said.
"As we leave for the last time, my only wish is continued success for this great country that I love so very much."
The outgoing prime minister – who announced he was standing down the morning after Britain voted to quit the European Union – also paid tribute to his officials and everyone who had "given so much support to me personally over these years".
"The incredible team at Number 10, the civil servants whose professionalism and impartiality is one of our country’s greatest strengths. And my political advisers, some of whom have been with me since the day I stood for my party’s leadership 11 years ago."
Cameron said the spirit of public service was one of Britain’s “most remarkable qualities”.
“I’ve seen that service day-in, day-out, in the incredible work of our Armed Forces, our intelligence agencies, and our police,” he said.
“It is something I always knew, but as prime minister you see it so directly that it blows you away.”
And he welcomed incoming prime minister Theresa May, who he said would “provide strong and stable leadership” and negotiate the “best possible” Brexit deal.