When Boris Johnson announced he had tested positive for coronavirus, Downing Street said Foreign Secretary Dominic Raab would deputise if the British prime minister was incapacitated.
Few expected him to do so, as Johnson and his office repeatedly maintained the prime minister's symptoms were mild.
But after Johnson was taken to hospital on Sunday night, and transferred to intensive care just 24 hours later, Raab now looks set to be in charge for the foreseeable future.
Raab was one of the most prominent figures in Britain's protracted and divisive process to leave the European Union, serving as Brexit minister under former premier Theresa May.
He quit after just three months in November 2018 in protest at May's doomed divorce deal with Brussels that he said offered too many concessions.
But when Johnson became Conservative party leader and prime minister after May's resignation in July last year, Raab was catapulted back into government.
His role as foreign secretary also carries the title first secretary of state, implying seniority over all other ministers except the prime minister and making him his de facto deputy.
The 46-year-old, who has law degrees from both Oxford and Cambridge universities, had ambitions himself for the top job, challenging Johnson for the Tory leadership after May quit.
Often combative, he holds a black belt in karate and is a keen boxer.
Raab's tilt for the top job marked him out as a threat to former London mayor Johnson due to his even more strident pro-Brexit views.
But he trailed in sixth in the leadership contest after a stuttering campaign that was marked by rows over his past views on militant feminism and preparedness to suspend parliament to force a no-deal Brexit.
His spell in the Brexit ministry also floundered, and was notable for his admission he "hadn't quite understood" the economic importance of the port in Dover.
As a recognised eurosceptic, Raab became the public face of Brexit but May also put a senior civil servant in charge of leading the negotiations with Brussels.
That left Raab personally and politically frustrated and unable to stop the plan May settled on.
Raab made much of his back-story in his leadership campaign.
His Czech-born Jewish father came to Britain in 1938 as a six-year-old refugee. He died of cancer when Raab was 12 and his mother brought him up in the Church of England.
He competed in karate for 17 years, making the UK squad.
After studies, he became an international lawyer at London legal firm Linklaters before joining the Foreign Office in 2000 as an advisor.
Raab was posted to The Hague in 2003 to head a team focused on bringing justice to war criminals including Slobodan Milosevic, Radovan Karadzic and Charles Taylor.
From 2006 to 2008, he was chief of staff to the Conservatives' home affairs spokesman David Davis while in opposition.
Climbing the ranks
Raab entered parliament in 2010 in the ultra-safe Conservative seat of Esher and Walton in the stockbroker commuter belt southwest of London.
He was named "Newcomer of the Year" in The Spectator magazine's Parliamentary Awards.
The same year, May, the then interior minister, slapped Raab down for calling feminists "obnoxious bigots".
He caused major problems for the then-prime minister David Cameron in 2014, with a backbench amendment on curbing the power of judges to block deportations under European rights laws.
Nearly 100 Conservatives supported him, singling him out as an up-and-coming force.
Cameron put Raab on the most junior government rung in the justice ministry in 2015, but he dropped off when May became prime minister in 2016.
Keen to freshen up the government with some younger faces a year later, May made him the junior minister for courts and justice.
She moved him across to become the junior housing minister in January 2018, then bumped him up to the Brexit job six months later.
Raab denied claims by his former diary secretary that he insists on the same lunch every day — reportedly a chicken and bacon sandwich, a smoothie and a mixed fruit pot.
Raab is married to Erika Rey-Raab, a Brazilian marketing executive. They have two young sons, Peter and Joshua.