Penny Mordaunt has become the UK's first female defence secretary after Gavin Williamson was sacked.
She was previously international development secretary, in charge of a multi-billion pound annual budget.
With a background as a naval reservist, and having served as an armed forces minister under David Cameron, Ms Mordaunt seems well prepared for the role.
She was seen as a frontrunner for the defence secretary position in 2017 when Michael Fallon was forced to quit the post, but lost out to Mr Williamson.
Ms Mordaunt was a high-profile campaigner for the Leave campaign during the 2016 EU referendum and underlined her pro-Brexit credentials by backing Andrea Leadsom in the subsequent Conservative leadership contest.
During the referendum campaign - while a defence minister - she prompted a row by telling the BBC's Andrew Marr Show that the UK could not veto Turkey joining the European Union. The then-prime minister contradicted her on ITV's Peston on Sunday an hour later.
The daughter of a paratrooper and a special needs teacher, Ms Mordaunt has two brothers, Edward and James, who is her twin, and has lived in her home town of Portsmouth since the age of two.
She was educated at Oaklands RC Comprehensive School and was the first member of her family to go to university.
Before studying philosophy at Reading University, she worked as a magician's assistant for a member of the Portsmouth and District Magic Circle, Will Ayling, author of The Art of Illusion and Oriental Conjuring and Magic.
She says on her website that she first became interested in politics working in hospitals and orphanages in post-revolutionary Romania during her gap year.
But Ms Mordaunt, 46, is probably best known outside Westminster for her appearance on ITV's celebrity diving show Splash! to raise money for charity.
She exited the contest in January 2014 after twice mistiming her back somersault from the 7.5m board but earned praise from Tom Daley and the other judges for her have-a-go attitude.
Later that year she was in the headlines again for a speech she gave in the Commons on poultry welfare, which turned out to be an excuse to slip some very un-parliamentary language into proceedings.
She admitted she had made the speech - with its liberal use of "lay", "laid" and "cock welfare" - as a bet.
"When I was at Dartmouth doing my reservist training, some of my marine training officers thought it would be a good idea to try and break the ladylike persona that I maintained throughout the whole of my course by getting me to yell particular rude words during the most gruelling part of our training, and I'm happy to say that they failed in that," she said.
"But during our mess dinner at the end of the course I was fined for a misdemeanour, and the fine was to say a particular word, the abbreviation of cockerel, several times during a speech on the floor of the House of Commons and mention all of the officers' names present."
MP for Portsmouth North since 2010, Ms Mordaunt is a former head of the Conservative Party's youth wing and was a press officer for William Hague when he was party leader, during which time she was seconded to work on George W Bush's 2000 election campaign in Washington.
"I was amazed at the similarities of the issues and tactics," she told The Daily Telegraph.
Before entering the world of Westminster politics, she was a press officer for Kensington and Chelsea Council and the Freight Transport Association, when she supported British truckers during French blockades.
She has also worked in the charity sector as a director of the Big Lottery Fund and Diabetes UK, where she set up services in developing countries particularly prone to the condition. She was also involved in David Willetts' abortive campaign to be Conservative leader in 2005 as his chief of staff.
On Twitter, Ms Mordaunt describes her two main interests as "freedom and cats".
And, in her maiden speech to Parliament in June 2010, she revealed that she had been named after the Royal Navy cruiser HMS Penelope.
"I point out to my critics," she added, "that HMS Penelope latterly became known as HMS Pepperpot because of her ability to endure massive amounts of shelling and remain afloat and able to return fire."