Throughout her extraordinary 70 year reign, the Queen has worked with 15 Prime Ministers.
From Winston Churchill to Liz Truss, the monarch held weekly audiences with the nation's political leaders to discuss their plans and offer wise counsel on the issues of the day.
The Queen met with the new Prime Minister just days ago - inviting her to form a Government - after the resignation of Boris Johnson and the conclusion of the Tory leadership contest.
The 96-year-old held an audience with Ms Truss at Balmoral on Tuesday, with photos of the private event released by Buckingham Palace to mark the transition of power.
Only two days later, the PM led tributes to the Queen as the "rock on which our country was built" and poignantly became the first person to say "God Save the King".
Winston Churchill (Conservative 1951-55)
The Conservative leader who had been re-elected following Clement Atlee's post-war Labour administration was the monarch's first prime minister after the death of her father, King George VI.
Sir Winston had nurtured the new Queen through her early years and once asked who she enjoyed meeting the most, she replied: "Winston, of course, because it was always such fun".
Anthony Eden (Conservative 1955-57)
Best known for his handling of the Suez crisis in 1956, the relationship between the Queen and Sir Anthony is said to have been more formal than his predecessor.
But he spoke warmly of their meetings - perhaps because the Queen made sure to act warmly towards him, in a bid to comfort him.
Harold Macmillan (Conservative 1957-63)
The prime minister - once seen huddled over a transistor radio as US astronaut John Glenn was hurtling through space - described the monarch as a "great support, because she is the one person you can talk to".
Alec Douglas-Home (Conservative 1963-64)
Sir Alec Douglas-Home reportedly had an awkward start - as he was previously a family friend of her mother's and House of Lords peer. He was unpopular as PM, leaving him open to attacks.
But while he was PM, only for a year before Labour won at the General Election, the pair were said to enjoy their weekly talks, and he helped the Queen name horses over the year.
Harold Wilson (Labour 1964-70 and 1974-76)
Harold Wilson endeared himself to the Queen, even as her first Labour prime minister, and his socialist leanings.
"They got on like a house on fire,” one long-standing member of the Labour Party said, as he used to join members of the royal family for riverside picnics at Balmoral.
Edward Heath (Conservative 1970-74)
Sir Edward Heath is said to have struggled with small talk and their weekly audiences have been described as “frosty”, possibly due to their differing views on the Commonwealth.
In 2012, it emerged that Sir Edward had fallen asleep during a dinner the monarch held with her ex-Prime Ministers.
The incident has emerged in an interview given by Sir John Major, in which the former PM spoke of his favourite private moments with the monarch.
Sir John said: "There was an occasion where I gave a private dinner for the Queen at Number 10 and all past Prime Ministers attended and Ted Heath, who was then very elderly.
"'I was sitting on one side of the Queen and Ted was sitting on the other, and he fell asleep.
"'I leaned across and said to the Queen: 'Ted has fallen asleep.' 'I know he has,' she said, 'but don’t worry, he’ll wake up a little later and we’ll say nothing about it,' and that’s exactly what happened.”
James Callaghan (Labour 1976-79)
James Callaghan managed to establish a warm rapport. He said about the Queen: “One of the great things about her is that she always seems able to see the funny side of life. All the conversations were very enjoyable,"
He said she was a good listener in their varied conversations.
Margaret Thatcher (Conservative 1979-90)
One of the Queen's longest-serving and divisive prime minister's, Baroness Thatcher reportedly found the traditional visit to Balmoral for a weekend uncomfortable.
When Baroness Thatcher died in April 2013, the Queen took the unusual step of attending her ceremonial funeral – a personal decision and an indication of the Queen’s respect for her first – and at the time her only – female Prime Minister.
John Major (Conservative 1990-97)
Sir John served as the Queen's ninth PM - and gave an insight into their weekly meetings, which were only witnessed by the monarch's pet corgis.
"We would sit down...and we would talk about whatever was relevant,” he said. "No third party ever attends those meetings.
"There’s nobody else ever there. No record of them is ever kept and nobody ever talks about what the content of those meetings might be. The only other living soul present is often the Queen’s corgis, they tend to amass around the chair.
"If they were bugged, all our state secrets would be apparent but to the best of my knowledge, that’s never happened.”
Tony Blair (Labour 1997-2007)
The former Labour leader became prime minister in the same year as Princess Diana's death and met with the monarch weekly for the next ten years.
Their relationship was said to have improved over the years.
.After the Queen's passing, Sir Tony said: "We have lost not just our monarch but the matriarch of our nation, the figure who more than any other brought our country together, kept us in touch with our better nature, personified everything which makes us proud to be British".
Gordon Brown (Labour 2007-2010)
The Labour Prime Minister between 2007 and 2010 was reported to have a good but formal relationship with the Royals.
After the monarch's passing on Thursday, he said the United Kingdom "and the entire world are joined together in mourning this evening".
"HM Queen Elizabeth II served this country to the last. I offer my sincere condolences to the Royal Family. May she rest in peace."
David Cameron (Conservative 2010-2016)
The former Tory prime minister was forced to make an apology to the Queen after being caught on camera telling the New York mayor Michael Bloomberg that she "purred down the line" when he called her to tell her the result of the Scottish referendum.
The pair, who are fifth cousins, twice removed, were said to get on well otherwise, as he worked with the monarch to update the law to allow older sisters to ascend to the throne before younger brothers ahead of the birth of the Duke and Duchess of Cambridge’s first child in 2012.
Theresa May (Conservative 2016-2019)
The second female prime minister during the Queen's 70-year reign paid tribute to the monarch at the Jubilee earlier this year, saying she had greeted all former PMs "with charm and consideration and with an impressive knowledge and understanding of the issues of the day".
When Ms May left office in July 2019, ITV's Royal Editor Chris said the Royal's respected her efforts to lead the country.
"While members of the Royal Family sit above political debate, I've heard some of them speak with admiration for the level of hard work and many hours of negotiation Theresa May has invested in her role over the last three years," he said.
Boris Johnson (Conservative 2019-2022)
Shortly after Boris Johnson took office, he requested the Queen prorogue Parliament - only for the Supreme Court to rule against his move, forcing him to apologise.
No 10 apologised a second time to Buckingham Palace over the Partygate scandal - after it emerged Downing Street held lockdown-flouting gatherings on the eve of Prince Philip's funeral in 2021.
But paying tribute to her on the Queen's Jubilee in June, Mr Johnson said she has an "unwavering dedication to this nation".
He added: "No monarch, by her efforts and dedication and achievement, better deserves the attribution of greatness. And for me, she is already Elizabeth The Great."
Liz Truss (Conservative 2022-present)
The monarch invited her last prime minister to form a government on Tuesday at Balmoral, following the resignation of Boris Johnson.
At 4.30pm on Thursday, Ms Truss was informed by the cabinet secretary Simon Case of the Queen's passing - before delivering a statement to the nation outside No 10.
The new prime minister described the monarch as the "rock on which our country was built" and paid tribute to the "passing of the second Elizabethan age".
