From David Cameron's last Prime Minister's Questions, to Theresa May meeting The Queen, here is how the day unfolded in pictures.Read the full story ›
The prime ministers of Canada and Belgium have joined leaders from around the world in congratulating Theresa May on becoming prime minister.
Justin Trudeau, the Canadian prime minister, issued a statement congratulating Mrs May and paying tribute to David Cameron.
Meanwhile, the prime minister of Belgium, Charles Michel, took to Twitter to congratulate Mrs May, saying he hopes the UK will be a "close partner" of Belgium.
Russian President Vladimir Putin has thanked David Cameron for his time as UK prime minister, and congratulated Theresa May on replacing him.
Theresa May kept her first speech as prime minister short and to the point, as she vowed to lead a "better Britain" outside the EU.Read the full story ›
Theresa May has pledged to fight key social injustices, including women earning less than men and black people being "treated more harshly" than white people by the criminal justice system.
Speaking in Downing Street in her first public address since becoming prime minister, Mrs May said the full title of her party - the Conservative and Unionist Party - is a reflection of the "precious, precious bond" between the nations of the United Kingdom but also the union between "every one of us - whoever we are and wherever we're from".
"That means fighting against the burning injustice that if you're born poor you will die on average nine years earlier than others," she said.
"If you're black you are treated more harshly by the criminal justice system than if you're white. If you're a white working class boy you're less likely than anybody else in Britain to go to university.
"If you're at a state school you're less likely to reach the top professions than if you're educated privately. If you're a woman you will earn less than a man.
"If you suffer from mental health problems, there's not enough help to hand. If you're young you will find it harder than ever before to own your own home.
"But the mission to make Britain a country that works for everyone means more than fighting these injustices. If you're from an ordinary working class family, life is much harder than many people in Westminster realise."
There was applause as Theresa May enters 10 Downing Street for the first time as prime minister.
Theresa May has taken office as the UK's second female prime minister.
She waved on the steps of 10 Downing Street with her husband Philip before entering what will be her new home.
In her first speech as PM, May vowed not to be driven by the interests of the privileged few but to "build a better Britain together".
Theresa May has set out her key pledges as Prime Minister in her first public address after taking office, saying her government would be driven by the needs of ordinary Britons.
Speaking outside Number 10, Mrs May said she would:
- Fight against the burning injustice that if you're poor you die sooner
- Give people more control over their lives
- Prioritise ordinary Britons not the wealthy few when it comes to taxes
The former Home Secretary also pledged to forge a new role for the country following its decision to leave the European Union.
"Following the referendum we face a time of great national change," she said.
"I know because we're Great Britain that we will rise to the challenge.
"As we leave the European Union, we will forge a bold new positive role for ourselves in the world, and we will make Britain a country that works not for a privileged few, but for every one of us."
Theresa May paid tribute to David Cameron, as she arrived in Downing Street as Britain's new prime minister.
Mrs May said she planned to lead a "One Nation" government in the "same spirit" as Mr Cameron.
Theresa May has arrived at Downing Street to take up her new post as prime minister.
There were cheers from one side and boos from the other as she walked to give her first speech.
There were similar scenes when Margaret Thatcher was made Britain's first female prime minister in 1979.