Liz Truss on Tuesday officially became Britain's new prime minister, at an audience with head of state Queen Elizabeth II after the resignation of Boris Johnson.
The former foreign secretary, 47, was seen in an official photograph shaking hands with the monarch to accept her offer to form a new government and become the 15th prime minister of her 70-year reign.
The symbolic ceremony took place at the sovereign's remote Balmoral retreat in the Scottish Highlands, as the queen, 96, was deemed unfit to return to London due to ill health.
"The queen received in audience the right honourable Elizabeth Truss MP today and requested her to form a new administration," Buckingham Palace said in a statement.
"Ms Truss accepted Her Majesty's offer and kissed hands upon her appointment as prime minister.
The last time the handover of power took place at Balmoral was in 1885, when Queen Victoria was on the throne.
Normally, the outgoing and incoming prime minister meet the queen in quick succession at Buckingham Palace in central London.
It has only been held once outside London since 1952, when Winston Churchill met the new queen at Heathrow Airport after the death of her father, King George VI.
Truss, who was announced winner of an internal vote of Conservative party members on Monday, after a gruelling contest that began in July.
She is expected to make her first speech as prime minister outside 10 Downing Street at about 4:00 pm (1500 GMT) on Tuesday -- weather permitting.
Heavy rain and storms are forecast, mirroring the gloomy economic situation that she and her new senior ministers will now have to tackle.
The appointments are due to be finalised before she hosts her first cabinet meeting and faces questions in parliament on Wednesday.
Business Secretary Kwasi Kwarteng is expected to become finance minister, with Attorney General Suella Braverman moved to the tricky brief of home secretary, and James Cleverly to foreign affairs.
If confirmed, it would mean no white men in any of Britain's four main ministerial posts for the first time ever.
The incoming prime minister faces a daunting to-do list, with the UK in the grip of its worst economic crisis in decades, with double-digit inflation and skyrocketing gas and electricity bills.
Truss, who touts herself as a free-market liberal, has promised tax cuts to stimulate growth, despite warnings that greater borrowing could make inflation worse.
British media reported on Tuesday that she would freeze energy bills for hard-pressed households and business which could cost some £100 billion ($116 billion).
The contrast to her beaten leadership rival Rishi Sunak's more cautious approach has opened another rift in the Conservative party that was already divided by Johnson's departure.
Recent opinion polls suggest a sizeable chunk of the British public have no faith in her ability to tackle the cost-of-living crisis.
A new poll by YouGov said only 14 per cent expect Truss -- the fourth Tory prime minister in six years -- to do a better job than Johnson.
Johnson, whose tenure was dominated by Brexit and Covid and cut short by a succession of scandals, earlier promised Truss his unswerving support as he made a farewell speech in Downing Street.
"I will be supporting Liz Truss and the new government every step of the way," he said, before leaving for Balmoral to cheers and applause from supporters.
He urged the Tories to put aside their ideological differences which have seen the party fight like cats and dogs over how best to tackle the energy crisis.
"If Dilyn (his dog) and Larry (the Downing Street cat) can put behind them their occasional difficulties then so can the Conservative party," he added.
But former newspaper polemicist Johnson failed to dampen speculation that he is eyeing a potential return to the political front line.
"Like Cincinnatus, I am returning to my plough," he said. Latin scholars were quick to point out that the Roman statesman eventually returned to politics.
Johnson, 58, remains popular among grassroots Tories as a charismatic election winner who took the country out of the European Union.
Despite repeated accusations of corruption and cronyism during his tenure, and an unprecedented police fine for breaking his own lockdown rules, Johnson is said to be smarting at having to leave.
Speculation has swirled that he could bide his time for a comeback, particularly if Truss struggles to overcome the country's many problems.
In her acceptance speech on Monday, Truss ruled out seeking her own mandate from the public at an early general election, vowing victory in 2024.