When the home secretary, Sir William Joynson-Hicks, is torn away from the pressing matter of the looming General Strike to witness the birth of Princess Elizabeth in 1926, in a tradition now mercifully consigned to history, no one imagines the newborn girl will be queen. Elizabeth is born third in line to the throne with her debonair uncle David, the Prince of Wales, the heir apparent.  Horse-mad from the earliest, Lilibet – as she is known – has her first riding lesson aged three, and acquires her first mount – a Shetland pony called Peggy – when she is four. The little princess ties dressing gown cords to her nursery bed posts as reins to drive her pretend horses. Some 30 toy horses are fed, watered, groomed and then “stabled” in a corridor each night.  Such innocent revelations about Elizabeth and her sister Margaret, born in 1930, are later serialised in the US publication Ladies’ Home Journal, courtesy of royal governess Marion Crawford. Publication leads to the hapless former servant being ostracised by the royal family and the phrase “doing a Crawfie” is thereafter used to refer to unwelcome disclosures by royal staff.  Crawfie later publishes The Little Princesses, confiding startling nuggets such as that when roused “Lilibet was quick with her left hook” while Margaret was “more of a close-in fighter, known to bite on occasions”. The former governess also documents how Lilibet once tipped a full ink pot over her own head while bored in a French lesson.  Uncle David becomes Edward VIII, but Princess Elizabeth’s dreams of life as a country wife are shattered when the government balks at the prospect of American Catholic divorcee Wallis Simpson as his choice of queen.  With the abdication crisis of December 1936, and her shy, stammering father crowned George VI, she becomes heiress presumptive. Only primogeniture can save her now, and she is seen on her knees before bedtime “ardently praying for a brother”, according to Countess Strathmore, her maternal grandmother.  Related: Queen photographed with youngest royals to mark 90th birthday  During a summer encounter with 13-year-old Elizabeth at the Royal Naval College in Dartmouth in 1939, distant cousin and dispossessed Prince Philip of Greece, 18, impresses with his agility by jumping over the college tennis nets several times. “I thought he showed off a good deal,” Crawfie sniffs later.  Elizabeth spends much of a decade dominated by war ensconced at Windsor, shielded from the blitz. In 1945 she joins the Auxiliary Territorial Service to become No 230873 second subaltern Elizabeth Windsor.  On her 18th birthday Elizabeth is given Susan, her first corgi and the founder of her own canine dynasty.  On a tour of South Africa with her parents, 21-year-old Elizabeth makes one of her most famous radio broadcasts. In a cut-glass accent she pledges: “I declare before you that my whole life, whether it be long or short, shall be devoted to your service and the service of the great imperial commonwealth to which we all belong.”  Officially engaged on her return, she and newly naturalised Lieutenant Philip Mountbatten marry in November 1947. The New York Times declares the nuptials “a welcome occasion for gaiety in grim England, beset in peace with troubles almost as burdensome as those of the war”. As a postwar bride Elizabeth is eligible for 200 extra clothing coupons. Philip’s sisters, who have married Germans, are not invited. Neither is the former Edward VIII and his wife, Wallis, both of whom have flirted with Hitler.  Prince Charles is born in 1948 and sister Anne follows in 1950. Elizabeth enjoys the relatively carefree life of a young naval wife with Philip, who is stationed in Malta. But, while on an official visit to Kenya, she is told of the death of her father. She flies back to Britain and is proclaimed Queen on 8 February 1952. Churchill is prime minister, the first of 12 to have served her.  The Suez crisis and Britain’s subsequent climbdown culminates in the resignation of the prime minister, Anthony Eden, on health grounds in 1957. The Queen is placed in a tricky situation regarding his successor when she is forced to choose between “Wab or Hawold” – Rab Butler or Harold Macmillan – as Lord Salisbury, with his speech impediment, famously put it in cabinet soundings. After taking advice she asks Macmillan to form a government, to the astonishment of Fleet Street, which has widely expected Butler.  She is sucked into another ugly Conservative party squabble in 1963, when an ailing Macmillan sneakily convinces her to choose Alec Douglas-Home as successor over Butler, the deputy prime minister. Feeling obliged to take his advice, she makes, according to the late historian Ben Pimlott, “the biggest political misjudgment of her reign”. The row that ensues leads the Conservatives to adopt Labour’s example and establish a leader selection process that will not embarrass the Queen again. The silver lining, according to aides at the time, is that Lord Home is much more her cup of tea than Butler, and the two can happily chat about dogs, shooting and Scottish estates.  In 1960 Andrew is born, followed four years later by Edward. John F Kennedy and his wife, Jacqueline, are guests at the palace.  This decade also sees the failure of the then postmaster general, Tony Benn, to remove the Queen’s head from stamps, though he does manage to get it shrunk on some later designs.  Eight days after the Aberfan disaster, which saw 144 people, including 116 children, killed by the collapse of a tip of coal waste, the Queen visits the Welsh village. A small girl presents her with a posy and card reading “from the remaining children of Aberfan”. The fact it took so long for this royal visit is something the Queen later regrets. “Aberfan. She got that wrong and she knows it,” Lord Charteris, her former private secretary, once replied when asked if she had ever put a foot wrong.  It is a less adoring public now, and Buckingham Palace believe cooperating with the 1969 fly-on-the-wall documentary The Royal Family will allow the monarch to connect more. Footage includes her having a barbecue at Balmoral with the soon-to-be invested Prince of Wales on salad dressing and Philip on sausages.  Philip does little to enhance this image of ordinariness, however, when he lets slip to the US broadcaster NBC that the civil list funds are so inadequate “we may have to move into smaller premises”. He’s already had to sell a small yacht, and may have to give up polo, he adds. A furore ensues leading to a parliamentary committee on the civil list, which serves to highlight that the Queen pays no tax and no death duties.  The silver jubilee sees a million crowd on to the Mall in London, street parties and an exceptional period of popularity – despite the Sex Pistols – as the Queen renews her 1947 pledge: “Although that vow was made in my salad days when I was green in judgment, I do not regret one word of it.” Charles’s fairytale wedding to Diana Spencer adds to the excitement surrounding “the Firm”.  The palace is shocked to the core in 1979 when the IRA assassinates Philip’s uncle Lord Mountbatten, along with a local boy, Mountbatten’s grandson and the dowager Lady Brabourne, by blowing up his fishing boat in Sligo, western Ireland.  The same year Anthony Blunt, her former surveyor of pictures, is unveiled as a Soviet spy.  Two years later Marcus Sarjeant, 17, fires six blanks at Elizabeth during the trooping the colour ceremony. The Queen wins accolades for her skill in handling her startled mount, Burmese, and Sarjeant is prosecuted under the Treason Act and sentenced to five years.  Palace security is found seriously wanting when unemployed decorator Michael Fagan manages to make his way into the Queen’s bedroom, where he comes face to face with the monarch.  The election of Britain’s first female prime minister brings a different dynamic. While the women are cordial to each other, some courtiers carp that Margaret Thatcher acts more queenly than the queen. There is serious embarrassment all round when the Sunday Times runs a sensational story headlined “Queen dismayed by uncaring Thatcher”, which says Elizabeth disagrees with many of Thatcher’s policies.  The story is subsequently explained away as being a misunderstanding by a reporter of a palace press officer’s briefing. The opposition leader, Neil Kinnock, refusing to capitalise on political gold, puts it down to “loose-lipped courtiers and wide-eared reporters”. Nevertheless, Thatcher’s reluctance to impose sanctions on apartheid South Africa causes problems for a queen who is also head of the commonwealth.  Three of the Queen’s four children get divorced, with Charles’s fairytale marriage imploding into “the war of the Waleses”. Andrew Morton’s sensational book Diana: Her True Story fuels the press. “Squidgygate”, an intimate call between Diana and gin heir James Gilbey, and “Camillagate”, an excruciatingly personal call between Charles and his then lover Camilla Parker Bowles, end up in the tabloids.  Then Windsor Castle burns down. A desolate Queen, in raincoat, sheds a tear for her favourite residence. In her 40th anniversary speech to guests at London’s Guildhall, she admits: “1992 is not a year I shall look back on with undiluted pleasure. In the words of one of my more sympathetic correspondents, it has turned out to be an annus horribilis.”  There is uproar when the government suggests paying for Windsor Castle’s repairs. The Queen ends up paying tax on her income, slimming down the civil list and funding the repairs by opening Buckingham Palace to a paying public.  Courtiers are shaken as a baying public decries the Queen as uncaring for staying at Balmoral, with grandchildren William and Harry, in the immediate aftermath of Diana’s death in a car crash in Paris in 1997. Anger dissipates when she returns to London, lowers the Buckingham Palace flag and makes an unprecedented TV address.  During her golden wedding celebrations, she praises Philip as “my strength and stay all these years”. Britannia, the royal yacht, is decommissioned, and rare royal tears are shed.  She loses the two women who know her best when her sister, Margaret, dies on 9 February 2002 and the Queen Mother weeks later on 30 March. Golden jubilee celebrations continue, including a palace pop concert to which she and Philip wear earplugs.  The trial of Diana’s former butler Paul Burrell for theft of her belongings collapses spectacularly when the Queen remembers he spoke to her about taking items for safe-keeping. A delighted Burrell exclaims: “The Queen came through for me.”  A pesky Mirror reporter lands an undercover job as royal footman and reveals to the world her love of Tupperware.  After many years of “can they, can’t they”, Charles and Camilla finally marry in 2005. The Queen, as head of the Church of England, does not attend the civil ceremony but is present at the church blessing, and throws a big party afterwards.  The Queen’s 80th birthday is widely celebrated and the BBC commissions Rolf Harris to paint an official portrait. The whereabouts of the picture today is a mystery.  At 81 Elizabeth overtakes Victoria as the UK’s oldest monarch. She is hailed when she becomes the first British monarch to travel to the Republic of Ireland in 100 years, in 2011. The following year she puts any personal feelings over Mountbatten aside when she shakes the hand of former IRA commander and now Northern Ireland’s deputy first minister, Martin McGuinness.  She makes a visit to Bergen-Belsen, her first ever to a former concentration camp.  Her 2012 diamond jubilee is declared a success as she survives being buffeted and soaked on a barge during the Thames river pageant, though Philip ends up being taken to hospital with a bladder infection.  The Queen surprises the world during the London Olympics by pretending to parachute into the opening ceremony, uttering the immortal line: “Good evening, Mr Bond.”  For monarchists it’s a job well done when her grandson, William, and his wife, Catherine, produce an heir – and a spare.  She becomes the UK’s longest reigning monarch but it is business as usual on the day she surpasses Victoria’s 23,226 days, 16 hours and 23 minutes.
As Elizabeth II marks her milestone birthday, we chart her life from horse-mad child to UK’s longest reigning monarch