Grant Shapps will take the reins at the Ministry of Defence (MoD) against a backdrop of war in Europe and with his predecessor warning the world will become more insecure and unstable.
Unlike Ben Wallace, whose expected resignation came on Thursday, Mr Shapps takes over as Defence Secretary without having served in the military.
Mr Shapps, who moves to the role from a stint as energy secretary, has held a number of senior posts in Government in recent years, but has had a chequered history with the Tories.
With his local grammar school education and a rock star relative who played guitar for The Clash, Mr Shapps has a slightly different background from many contemporaries at the top of the Conservative Party.
While his family leaned more towards music – brother Andre Shapps played keyboards with post-punk band Big Audio Dynamite and his cousin, Mick Jones, was a founder member of The Clash – Mr Shapps found his passion in politics from a young age, becoming national president of the Jewish youth organisation BBYO.
In his early 20s, he set up a marketing and printing business before contesting his first parliamentary seat in 1997. He eventually ousted Labour’s Melanie Johnson in 2005 to become MP for Welwyn Hatfield in Hertfordshire, being elected the Tory party’s vice chairman the same year.
In 2007, he became shadow housing minister and after the 2010 general election he served as minister of state for housing and local government, being appointed to the Privy Council that June.
In September 2012, he was appointed co-chairman of the Conservative Party, and also held the position of minister without portfolio at the Cabinet Office.
His rapid rise stalled at the height of the 2015 general election campaign when he was accused of anonymously editing his own entry and those of other Conservative politicians on internet encyclopaedia Wikipedia.
The disclosure that Mr Shapps, or someone acting on his behalf, was suspected of engaging in “sock puppetry” – creating a fake online identity for improper purposes – proved embarrassing to the Tories.
At the time, then prime minister David Cameron stood by him, insisting he was doing a “great job”, while Mr Shapps denied the allegations and dismissed them as “bonkers”.
An investigation by Wikipedia found no definitive evidence linking the account used to alter the entries with Mr Shapps, and the encyclopaedia administrator who blocked the account and revealed the allegations to the media was criticised in an internal inquiry.
After the election, Mr Shapps was removed from the post of party chairman and made a minister at the Department for International Development – a move widely seen as a demotion.
He was forced to resign from that post after six months when it emerged that he had been warned about bullying among young party activists almost a year before 21-year-old Elliott Johnson killed himself.
Mr Shapps denied being informed about any allegations of bullying, sexual abuse or blackmail, but quit his post saying “responsibility should rest somewhere”.
Just months before the Wikipedia scandal, Mr Shapps was accused of having breached the codes of conduct for ministers and MPs when it was revealed he held a second job after entering Parliament.
He was exposed as having continued working as a marketer of get-rich-quick schemes under the pseudonym Michael Green.
Having been instrumental in a rebellion against Theresa May and Boris Johnson’s path to power, Mr Shapps returned to the top table in 2019 as transport secretary.
Planes enthusiast Mr Shapps oversaw the transport department during the Covid-19 pandemic and the ensuing airport chaos as travel resumed, and faced criticism for failing to engage with unions over industrial action.
But the Johnson ally was seen as a competent public performer and often sent out to do the media rounds by the then prime minister.
When Mr Johnson resigned in June 2022, Mr Shapps launched a Tory leadership bid of his own, but it was short-lived and he became a major backer of Liz Truss’s rival Rishi Sunak.
After Ms Truss beat Mr Sunak in the contest, Mr Shapps again found himself demoted to the backbenches.
Seen as a sharp-elbowed plotter, Mr Shapps is said to have recorded Tory colleagues’ doubts about Ms Truss in a running spreadsheet – and those doubts accumulated quicker than most expected.
With Ms Truss on the ropes and Suella Braverman departing as home secretary – before returning to the role under Mr Sunak – Mr Shapps was given one of the great offices of state.
But his time as home secretary lasted less than a week, with the Truss premiership collapsing in record time.
Mr Sunak took over as Prime Minister and Mr Shapps remained in the cabinet.
He was given the role of secretary of state for business, energy and industrial strategy, and when that department was split in February, Mr Shapps took over as head of the newly created Department for Energy Security and Net Zero.
He raised eyebrows earlier this year when he made clear in eccentric fashion that he would continue to use TikTok on his personal phone, despite a ban on Government devices driven by security fears.
The then energy secretary posted a clip to the social media app from movie The Wolf Of Wall Street in which Leonardo DiCaprio, portraying a New York stockbroker, declares he is “not f****** leaving” and the “show goes on”.
At the time, China hawks on the Tory benches called for ministers not to use the app, owned by Chinese internet company ByteDance, on their personal phones.
Mr Shapps said the ban on Government devices was sensible and insisted he was taking security precautions. He still has an account, which has nearly 15,000 followers.
While energy secretary he also accused Russian President Vladimir Putin of using energy as a “weapon of war”, and his time in office means he should enter the MoD with a strong grounding in how the conflict in Ukraine is affecting business and consumers.
Taking over the role of Defence Secretary from Mr Wallance, Mr Shapps will no doubt be seen as having big shoes to fill. His predecessor received widespread praise for his response to the conflict, and was much liked by his party. Mr Wallace was also able to draw on his own experience in the military when addressing difficult issues such funding and cuts to the Army.
Mr Wallace’s departure also marks an end to a period of relative stability at the top of the MoD, having held the post of defence secretary for four years. Mr Shapps, by contrast, is taking on his fifth role in the Cabinet in the last year alone.
And with the UK having played a prominent role in supporting Ukraine so far, and with the conflicting ongoing, Mr Shapps will need to find his feet quickly at the MoD. The world will be watching.
