Kemi Badenoch has been elected leader of the Conservative Party.
The former business secretary was declared the winner at an event in central London on Saturday, defeating rival Robert Jenrick by 53,806 votes to 41,388.
She becomes the first black woman elected to lead a major British political party, and the fourth woman to lead the Conservative Party after Margaret Thatcher, Theresa May and Liz Truss.
The North West Essex MP will replace Rishi Sunak as leader of the Opposition and seek to chart a path back to power for the Tories after their disastrous election defeat in July.
They face a significant challenge, with just 121 MPs after an election that saw the party lose seats to Labour, the Liberal Democrats and Reform.
In a speech following her victory, Ms Badenoch acknowledged that her party's task was "tough but simple", saying the Tories had to hold the Government to account and develop a "clear plan" for government.
She added that the party had to be "honest" about the "fact we made mistakes" and "the fact that we let standards slip".
She said: "The time has come to tell the truth, to stand up for our principles, to plan our future, reset our politics and our thinking, and to give our party and our country the new start they deserve.
"It's time to get down to business, it's time to renew."
Both her predecessor Rishi Sunak and Prime Minister Sir Keir Starmer congratulated Ms Badenoch on her victory.
Mr Sunak urged the Conservatives to unite behind their new leader, saying: "I know that she will be a superb leader of our great party. She will renew our party, stand up for Conservative values, and take the fight to Labour."
Sir Keir said: "The first Black leader of a Westminster party is a proud moment for our country.
"I look forward to working with you and your party in the interests of the British people."
But Labour Party chairwoman Ellie Reeves said the Conservative leadership campaign showed the party had "learned nothing since the British people resoundingly rejected them in July".
She said: "They could have spent the past four months listening to the public, taking responsibility for the mess they made and changing their party.
"Instead, Kemi Badenoch's election as leader shows they're incapable of change."
A YouGov poll published ahead of the result found four in 10 voters had an unfavourable view of Ms Badenoch, including 29% of Conservative voters, while Britons were more likely to think Labour leader Sir Keir Starmer would make a better prime minister.