LONDON — Britain’s Conservative Party made history last weekend, becoming the country’s first major party to elect a Black woman as leader.

And yet this milestone was reached not by a party of the progressive center-left but by Britain’s oldest and most traditional conservative political force.

“I’m glad because it shows that my country and my party are actually places where it doesn’t matter who you are or what you look like,” the new leader, Kemi Badenoch, told the BBC on Sunday. After all, the Conservatives have broken glass ceilings before, picking all three of Britain’s female prime ministers, as well as its first leader who wasn’t white, Rishi Sunak.

Now 44, Badenoch was born in London and raised in Nigeria, returning to Britain when she was 16. In her first parliamentary speech, in 2017, she declared, “To all intents and purposes, I am a first-generation immigrant.”

She will now lead a party that has struck an increasingly harsh tone on immigration, a shift that mirrors her own changed views on the subject.

Her rise to the top echelon of British politics is the result partly of determination, hard work and a fearlessness that have helped her survive brutal infighting within her party in recent years. Claire Coutinho, a fellow Conservative lawmaker, wrote on social media that “Kemi’s fierce intellect and love of Britain will make her an excellent leader.”

But she has also benefited from good fortune and a concerted effort by former Prime Minister David Cameron to diversify the Conservative Party almost two decades ago.

“The reason she has been able to advance so rapidly through the party is the politics that David Cameron put in place — because he felt that the Conservative Party didn’t look enough like modern Britain,” said Robert Ford, a professor of political science at the University of Manchester.

The irony is that Cameron’s brand of liberal Conservatism has ended up benefiting Badenoch, a staunch opponent of “woke” diversity policies. Cameron’s deliberate recruitment of parliamentary candidates who were female and not white “is the kind of thing she is scathingly critical of,” Ford added.

Plain-speaking and sometimes antagonistic, Badenoch has a reputation for wading into debates on identity politics. Her pitch to become party leader was that she is “Labour’s worst nightmare because they can’t portray me as prejudiced,” an apparent reference to her racial identity.

Less well scripted were her comments, during the leadership campaign, suggesting that maternity pay was excessive and joking that a minority of civil servants performed so poorly that they should be in jail. Both were seized on by critics as the kind of unforced errors that could prove damaging to the Conservatives if they want to win back centrist voters.

Badenoch is a “high risk, high return” leader, Ford said.

“She is prone to say things that can blow up in her face and is not so quick to row back on them,” he said. But on the plus side, he said: “She gets attention.”

Badenoch was born in 1980 to a mother who was a lecturer in physiology and a father who was a doctor. Her parents were prosperous enough for their eldest daughter, Kemi, to be born in a private hospital in Wimbledon, in southwest London, before returning to Lagos, the Nigerian city where she was raised.

Initially she lived a comfortable life but, after political and economic upheavals, her family’s fortunes declined. Years later, she recalled “doing my homework by candlelight because the state electricity board could not provide power,” and fetching water from a nearby well when the faucets ran dry, because of failures by the nationalized water company. These experiences contributed to her preference for a small state. “I was unlucky enough to live under socialist policies. It’s not something I’d wish on anyone,” she wrote.

At 16, Badenoch returned to London to stay with friends, working part time at McDonald’s as she studied. She has recalled being disappointed by her teachers’ low expectations but went to Sussex University to study computer systems engineering.

Asked later what formed her Conservative views, Badenoch pointed to her experience at college “among snotty, middle-class north Londoners” who talked of helping Africans. “These stupid lefty white kids didn’t know what they were talking about,” she said in an interview this year with The Times of London, adding that she believed a campaign to boycott Nestlé over its promotion of infant formula in African countries was ill informed. “That instinctively made me think, ‘These are not my people.’ ”

Sunder Katwala, the director of British Future, a research institute, described Badenoch’s rise as “a remarkable personal achievement,” adding that she was “incredibly formed by the experience of being a young Black African woman who comes to Britain, and a lot of that strengthens her to become conservative.” Badenoch, he said, is very positive about British democracy because she is comparing it to the Nigeria she grew up in — “whether the lights are on or not, or whether you have to pay bribes.”

When Cameron became leader of the Conservatives in 2005, he concluded that the Tories were “the oldest political party in the world — and we looked it.” Intent on diversifying the party, he oversaw a policy in which party members were encouraged to pick parliamentary candidates from a curated list, half of whom were female and a large proportion of whom were Black or from ethnic minority backgrounds.

In 2010, Badenoch, then Kemi Adegoke, ran for election in a pro-Labour district in south London where she unsurprisingly lost. But the campaign brought her close to the man she was to marry, Hamish Badenoch, a privately educated Conservative activist, now a managing director at Deutsche Bank.

In an interview with The Times of London, Kemi Badenoch acknowledged that her reputation for being confrontational extends to home life. “He thinks my capacity to tolerate conflict is too high,” she said of her husband. “He says, ‘You’re the politician in the family and I’m the diplomat.’ ”

A supporter of Brexit, Badenoch prospered under three Conservative prime ministers and was promoted to the Cabinet in 2022.

Her position on immigration has hardened in recent years. In comments from 2018 that recently resurfaced, she welcomed the Conservative government’s proposal to relax restrictions on visas for skilled migrants. But net migration has tripled since Brexit, and she said she had since changed her mind.

Badenoch now argues that “numbers matter but culture matters more,” adding that the most important factor is who is coming to Britain and what their values and aspirations are.