Queen Elizabeth ll saw 14 prime ministers come and go during her reign, and had just appointed a 15th days before her death on Thursday evening.
During her 70 years on the throne, the Queen held weekly private "audiences" with her Prime Ministers.
What was said in those meetings was rarely publicised, as it is the sovereign's role as head of state to remain politically neutral.
Under Britain's constitutional monarchy, the Queen is head of state but has little direct power. However, she was not without influence.
The Queen's views in those private meetings and the extent of the monarch's political influence was often a subject of intense speculation.
These are the 15 prime ministers that served during her reign and key moments in their relationships with the Queen.
1. Winston Churchill 1951-1955
Elizabeth was just 25 when her father King George VI died and she became Queen on February 6, 1952.
Then prime minister Winston Churchill's first reaction to the King's death was to complain that the new Queen was "only a child", but he was won over within days and eventually became an ardent admirer.
"All the film people in the world, if they had scoured the globe, could not have found anyone so suited to the part," Churchill once said, according to his biographer, Lord Moran.
Churchill suffered a stroke and eventually resigned in 1955.
The Queen wrote him a letter saying no-one would "ever for me be able to hold the place of my first prime minister, to whom both my husband and I owe so much and for whose wise guidance during the early years of my reign I shall always be so profoundly grateful".
2. Anthony Eden 1955-1957
Many of Anthony Eden's audiences with the Queen were spent discussing Princess Margaret's potential engagement to divorced Group Captain Peter Townsend.
Before 2002, the Church of England did not allow divorcees to remarry in church, making the marriage "unsuitable" and an issue of political contention.
Margaret gained worldwide sympathy in 1955 when she publicly renounced their plans to wed.
But Eden's tenure as Prime Minister was marred by the failures of the Suez Crises — a Cold War episode in which Israel, France, and the United Kingdom sought to regain Western control of the Suez Canal by invading Egypt.
The invasion failed in just over a week and Eden resigned shortly thereafter, marking the end of an era for Great Britain as a significant global power.
3. Harold Macmillan 1957-1963
In 1957, the Queen was called on to appoint a new British Prime Minister following Eden's sudden resignation.
Conservative politician Harold MacMillan accepted her invitation.
Macmillan once noted that Elizabeth II "means to be a queen and not a puppet", and that she had the "heart and stomach of a man".
The new prime minister praised the Queen's knowledge of foreign affairs.
"She showed, as her father used to, an uncanny knowledge of details and personalities," he wrote.
4. Alec Douglas-Home 1963-1964
After Macmillan became ill and resigned, Alec Douglas-Home was chosen to succeed him.
Douglas-Home was well known to the Queen, having been a childhood friend of her mother.
But he served for just under a year.
After narrow defeat in the general election of 1964, Douglas-Home resigned from the leadership of his party.
His premiership was the second briefest of the 20th century, lasting two days short of a year.
5. Harold Wilson 1964-1970 and 1974-76
Harold Wilson was the Queen's first Labour prime minister.
His tenure saw the relaxing of many of the United Kingdom's social conservatisms, including the abolishment of capital punishment and the decriminalising of male homosexuality in England and Wales, as well as relaxing divorce laws and liberalising birth control and abortion law.
In response to the outbreak of the Troubles in Northern Ireland, Wilson deployed British forces in Operation Banner, which would continue to stoke the sectarian violence in Northern Ireland for over three decades.
Wilson went on to become known as one of the Queen's favourite prime ministers.
He was defeated in the 1970 election by Edward Heath, but returned to power in 1974 for a second term.
6. Edward Heath 1970-1974
The Heath government is best remembered for bringing the United Kingdom into closer economic relations with Europe, eventually joining the European Communities, a collection of organisations that would later become the European Union.
Heath was reported to have had a difficult relationship with the Queen.
He died in 2005 at the age of 89, and allegations of child sexual abuse surfaced in 2018 during a wide-ranging investigation of historical child abuse.
7. James Callaghan 1976-1979
James Callaghan's years in government were dominated by economic recession and trouble with unions.
By 1976, inflation had hit almost 17 per cent.
His controversial decision to seek an emergency loan from the International Monetary Fund created significant tensions within the cabinet at the time.
Callaghan was known as a devoted royalist and he established a good rapport with the Queen.
He was the only Prime Minister to have also held the other three great offices of state: Chancellor of the Exchequer, Home Secretary and Foreign Secretary.
8. Margaret Thatcher 1979-1990
Margaret Thatcher was the first female Prime Minister to be appointed by Queen Elizabeth II, and the relationship between the two figures was often scrutinised.
Thatcher would later write on the accusations of their fraught relationship that "stories of clashes between 'two powerful women' were just too good not to make up".
Thatcher was given the moniker the "Iron Lady", and is remembered as a shrewd Conservative prime minister who deregulated the economy, privatised national companies, gutted trade unions, saw Britain through the Falklands War, and survived an attempted Provisional IRA assassination in the 1984 Brighton hotel bombing.
She was the Queen's longest-serving prime minister.
In 1995, Elizabeth II appointed Thatcher to the Order of the Garter, the highest order of chivalry in the UK.
9. John Major 1990-1997
John Major was the first Prime Minister to be appointed by the Queen who was younger than her.
After usurping Thatcher as Conservative leader, Major would continue to champion his predecessor's social and fiscal conservative policies: entering the Gulf War, steering the country through a recession, and the privatisation of various industries.
It was Major who announced to the cabinet that Prince Charles and Princess Diana would be separating in 1992.
That year, the Queen saw the breakdown of the marriages of three of her children and a devastating fire at Windsor Castle.
Major once said: "One can say to the Queen absolutely anything. Even thoughts you perhaps don't want to share with your cabinet."
It was during his administration that the Queen began voluntarily paying income tax.
10. Tony Blair 1997-2007
Tony Blair was the first prime minister to have been born during the queen's reign — a fact the monarch brought up at their first meeting.
He recalled that she told him: "You are my 10th prime minister. The first was Winston. That was before you were born."
A key player in the global war on terror, Blair campaigned on the promise of a 'new Labour', distancing himself and his party from traditional labour politics and socialist values.
While regarded for his progressive social policies — including civil partnership for same-sex couples, a national minimum wage, freedom of information, and the UK's Human Rights Act — the 2001 invasion of Afghanistan and the 2003 invasion of Iraq proved to be unpopular among voters.
11. Gordon Brown 2007-2010
As prime minister, Gordon Brown oversaw the United Kingdom during the global financial collapse.
While he was able to bail out the banks in a bid to triage the economy, the acquisitions significantly increased the United Kingdom's national debt.
Brown regularly sparred with Murdoch-owned outlets.
While his government was able to pass the world's first climate Change Act, a major loss of seats led to a hung parliament and an eventual Conservative-led coalition, paving the way for David Cameron.
In a royal first, the Queen allowed Brown's wife and children to attend his final audience with her.
12. David Cameron 2010-2016
David Cameron's tenure as Prime Minister was marked by the lingering difficulties of the Great Recession, which his conservative government sought to fix through austerity measures and large-scale changes to healthcare and welfare in the United Kingdom.
Cameron privatised the Royal Mail and oversaw the 2012 London Olympics.
While his foreign policy led to military interventions in Libya, he lost a foreign policy vote over proposed military action against Syria's Bashar al-Assad.
Cameron was the youngest serving prime minister during Elizabeth's reign.
He attended the Heatherdown School with Prince Edward, and was a distant relative of the royal family.
13. Theresa May 2016-2019
The three-year tenure of Theresa May, Britain's second female prime minister, was almost entirely consumed by Brexit.
May tried three times to get Parliament to back her Brexit deal and resigned after she repeatedly failed.
May and the Queen, both devout Christians, enjoyed a pleasant relationship.
In a moving tribute following her death, May described the Queen as the "most impressive head of state", with a "great warmth" and "a great sense of a humour".
"It was the honour of my life to serve her as prime minister," she said.
14. Boris Johnson 2019-2022
Boris Johnson will go down in history as the prime minister who "got Brexit done," but his tenure was defined by his handling of the coronavirus pandemic and scandals over rule-breaking government parties and lapses of ethical judgement.
A few months into his time as prime minister, Johnson apologised to the Queen after the Supreme Court ruled his advice to her to suspend Parliament for five weeks had been "unlawful".
In July 2022, members of his government began to quit en mass, forcing him to announce his resignation.
Following the Queen's death, Mr Johnson said the death of the only monarch most Britons have ever known would provoke "a deep and personal sense of loss – far more intense, perhaps, than we expected".
15. Liz Truss 2022-present
British Prime Minister Liz Truss was appointed by the Queen just 48 hours before her death.
Truss won a Conservative leadership contest to replace Johnson as leader of the governing party on Monday.
In a break from tradition, Truss flew to Balmoral Castle in Scotland to meet the Queen, who formally appointed her as Prime Minister in a ceremony on Tuesday.
It was to be the Queen's last constitutional action.
In an address to the nation, Ms Truss pronounced the country "devastated" and called Elizabeth "the rock on which modern Britain was built".
