Penny Mordaunt has replaced Priti Patel as International Development Secretary.
The 44-year-old Brexiteer was promoted in a mini-reshuffle of Conservative MPs after Ms Patel's departure – the Government's second Cabinet resignation in less than a week.
Ms Mordaunt, a Navy reservist, has had a long political career but a relatively short time in Parliament – only elected in 2010 and holding a handful of junior roles in the work and pensions, defence and communities departments.
She used to work for former Tory leader William Hague, and was head of foreign press for George W Bush's presidential campaign in 2000.
A savvy media operator, she sparked headlines in 2013 for a speech on animal welfare packed with innuendos – after losing a bet with fellow Royal Navy friends.
The Portsmouth North MP told critics when the prank was revealed afterwards: "If I have offended anyone, I'm sorry. Feel free to beat me up over it."
She also featured in celebrity TV diving show 'Splash!' – donning a swimsuit to plunge from a diving board to raise £7,000 for her local lido in 2014.
Unlike her predecessor – who suggested the international development department should be abolished before going on to head it – Ms Mordaunt is a strong supporter of the UK's foreign aid budget.
She tweeted in 2014 that she would back a move binding the Government to spend 0.7% of gross national income on aid.
Ms Mordaunt was summoned to Downing Street on Thursday afternoon to learn of her promotion.
She did not speak to reporters, but jumped into a ministerial car to be driven to her new department at the top of Whitehall.
In Parliament today to vote for the international development bill. Commits us to spend 0.7% on aid.
— Penny Mordaunt MP (@PennyMordaunt) December 5, 2014
She was replaced as disability minister by Sarah Netwon, a former junior minister in the Home Office.
And in the first promotion of new Conservative MPs into the Government, Victoria Atkins became Ms Newton's replacement.
It is the second mini-reshuffle in a week – after Ms Patel followed Sir Michael Fallon out of the Cabinet.
But while some were angry about Ms Patel's departure, there is significantly less hostility to her replacement's appointment than Sir Michael's.
Last week, the party was in uproar over Gavin Williamson being appointed Defence Secretary – with one minister telling Sky News the Prime Minister was "so weak she's allowed the inexperienced chief whip to appoint himself".Let's