Queen 90th birthdayQueen Elizabeth II, Britain's longest-serving monarch, turns 90 on Thursday 21 April 2016. She overtook her great-great-grandmother Queen Victoria's record time on the throne in September 2015, and is also Britain's oldest reigning monarch.
Elizabeth Alexandra Mary was born at 2.40am at 17 Bruton Street, Mayfair, on 21 April 1926, during the reign of her grandfather, King George V. As a young princess, Elizabeth had not expected to become monarch as her father only took the crown when his elder brother, Edward VIII, abdicated in 1936 to marry American divorcee Wallis Simpson.
She was 25 when she ascended to the throne on 6 February 1952, following the sudden death of her father, King George VI, at the age of 56.

1926: Family portrait of the Duke and Duchess of York (later King George VI and Queen Elizabeth) with the newborn princess (later Queen Elizabeth II)
Universal History Archive/UIG via Getty Images
1928: Princess Elizabeth, aged two, poses wearing a party dress
The Print Collector/Print Collector/Getty Images
July 1936: Princess Elizabeth hugs a corgi
Lisa Sheridan/Studio Lisa/Getty Images
12 October 1940: Princess Elizabeth makes her first radio broadcast, accompanied by her younger sister Princess Margaret
Getty Images
8 July 1941: Princess Elizabeth and Princess Margaret Rose play with their pet chameleon in the grounds of Windsor Castle
Getty Images
23 December 1944: Princess Elizabeth appearing in a production of Old Mother Red Riding Boots, a royal family pantomime
Lisa Sheridan/Studio Lisa/Getty Images
18 April 1945: Princess Elizabeth changes the tyre of a vehicle as she trains as an ATS Officer during World War Two
Central Press/Hulton Archive/Getty Images
8 May 1945: (From left) Princess Elizabeth, Queen Elizabeth, prime minister Winston Churchill, King George VI and Princess Margaret Rose wave from the balcony of Buckingham Palace during VE Day celebrations
Reg Speller/Getty Images
9 July 1947: Princess Elizabeth, Philip Mountbatten, Queen Elizabeth (the future Queen Mother), King George VI and Princess Margaret pose in Buckingham Palace on the day the engagement of Princess Elizabeth and Philip Mountbatten was officially announced
July 1947: Princess Elizabeth poses in the state apartments at Buckingham Palace upon her engagement to Prince Philip
Hulton Archive/Getty Images
20 November 1947: Princess Elizabeth and Prince Philip pose at Buckingham Palace after their wedding ceremony which was held at Westminster Abbey
Topical Press Agency/Getty Images
14 December 1948: A Cecil Beaton portrait of Princess Elizabeth with her infant son Prince Charles (born on 14 November)
Keystone-FranceGamma-Rapho via Getty Images
circa 1950: A Cecil Beaton portrait of Princess Elizabeth in the drawing room of Clarence House
Bettmann Archive/Getty Images
circa 1952: Princess Elizabeth and and husband Philip hold their two children, Charles and Anne
28 September 1952: Princess Elizabeth watches her son Prince Charles playing in his toy car at Balmoral
Lisa Sheridan/Studio Lisa/Getty Images
8 February 1952: Queen Elizabeth II is greeted by Sir Winston Churchill, Clement Attlee, Anthony Eden and Frederick James Marquis as she returns from Kenya. She was proclaimed Sovereign of each of the Commonwealth Realms two days earlier, upon the death of her father King George VI. Princess Elizabeth heard the news of her father's death while staying at Treetops, a game lodge in Kenya
8 February 1952: A ceremony is held in London for the proclamation of Queen Elizabeth II's accession to the throne
2 June 1953: Queen Elizabeth II, accompanied by Prince Philip, waves to the crowd from the balcony at Buckingham Palace after being crowned at Westminster Abbey. Her coronation was the first worldwide televised event

The year she became queen, Winston Churchill was prime minister, Harry Truman was US president, Joseph Stalin was leader of the Soviet Union, the Korean War was raging and Britain announced it had the atom bomb. Since becoming queen, she has seen 12 prime ministers and 12 US presidents. She has witnessed the intensification and end of the Cold War and the rise and fall of the Berlin Wall.

16 May 1954: Queen Elizabeth II and her children Prince Charles and Princess Anne wave to the crowd from a balcony of Buckingham Palace after returning from a trip
2 February 1956: The Queen inspects men of the newly-renamed Queen's Own Nigeria Regiment, Royal West African Frontier Force, at Kaduna Airport, Nigeria
Fox Photos/Hulton Archive/Getty Images
circa 1960: The Queen plays with her daughter Anne
25 January 1961: The Queen perches in a howdah on the back of an elephant in Benares, during her tour of India
Hulton Archive/Getty Images
26 January 1961: The Queen and Prince Philip pose with the Maharaja and Maharani of Jaipur after a tiger shoot in Jaipur, India
1965: The Queen and Prince Philip, with their children (left to right) Edward, Anne, Charles and Andrew, celebrate the Queen's 39th birthday at Windsor
Keystone/Getty Images
30 July 1966: England captain Bobby Moore holds the Jules Rimet trophy aloft after receiving it from the Queen upon their 4 -2 victory over West Germany in the the World Cup final at Wembley Stadium
Fox Photos/Hulton Archive/Getty Images
11 July 1969: The Queen holds the hands of her 20-year-old son Charles during his investiture as Prince of Wales at Caernarfon Castle
April 1973: Prince Philip looks on as the Queen uses a camera at the Badminton Horse Trials
Tim Graham/Getty Image
1974: The Queen arrives at Aberdeen airport with her corgis to start her holidays in Balmoral
Anwar Hussein/Getty Images
April 1976: The Queen poses for a portrait on her 50th birthday, in Windsor
February 1977: Queen Elizabeth II poses for a special Jubilee picture in the Throne Room of Buckingham Palace, after she had delivered the traditional Queen's speech at the 1976 official State Opening of Parliament. She wears the Imperial State Crown and the Robe of State. Around her neck is the Jubilee Necklace of diamonds and pearls and the chain is the Collar of the Order of the Garter
7 June 1977: Queen Elizabeth ll greets the public during a Silver Jubilee walkabout
Anwar Hussein/Getty Images
17 February 1979: Her Majesty wears a blue outfit with a turban-style hat and sapphire brooch during a visit to Riyadh in Saudi Arabia
Tim Graham/Getty Images
May 1979: The Queen, wearing a pink cape, attends the Royal Windsor Horse Show
Tim Graham/Getty Images
circa 1980: The Queen, wearing a green coat and matching hat, laughs as she attends the Royal Windsor Horse Show
Tim Graham/Getty Images
29 July 1981: Prince Charles and Princess Diana kiss on the balcony of Buckingham Palace after their wedding. They are surrounded by their bridesmaids and pageboys as well as Queen Elizabeth Il, Prince Edward and the Queen Mother
Tim Graham Photo Library/Getty Images
29 July 1981: Members of the British and European royal families surround Prince Charles and Princess Diana after their wedding
4 August 1982: Princess Diana holds her son Prince William, while Prince Charles, Prince Philip, the Queen and the Queen Mother look on, at Buckingham Palace after William's christening ceremony
Fox Photos/Getty Images
18 September 1982: Prince Andrew talks to his mother as his father looks on, aboard the air carrier HMS Invincible, upon his return from the Falklands war, where he served as a helicopter pilot
October 1982: The Queen and Prince Philip visit the Solomon Islands during a tour of the South Pacific
Anwar Hussein/Getty Images
21 December 1984: The Queen and other members of the royal family laugh at the antics of young Prince William as his brother Harry is christened at Windsor Castle
Anwar Hussein/Getty Image
11 May 1985: The Queen applies lipstick as she waits for Prince Phillip to enter the ring with his horse team at the Windsor Horse Show
David Levenson/Getty Images
23 July 1986: Prince Andrew and his bride Sarah Ferguson, the Duchess of York, wave to crowds from the balcony of Buckingham Palace while Queen Elizabeth II and the Queen Mother look on

The queen and the royals have endured some low points, particularly in the 90s, during the divorces of her sons Charles and Andrew and the subsequent death of Princess Diana. However, the popularity of the royals has rebounded with the marriage of Prince William to Kate Middleton and the arrival of their two children, Prince George — now third in line to the throne — and Princess Charlotte.

5 September 1997: The Queen and Duke of Edinburgh look at the mass of floral tributes laid outside Buckingham Palace in memory of Diana, Princess of Wales
1 January 2000: The Queen joins hands with the Duke of Edinburgh, Prime Minister Tony Blair and Cherie Blair to sing Auld Lang Syne at midnight during New Year's celebrations at the Millennium Dome
11 July 2000 : The Queen Mother declines the hand of her grandson Prince Charles as she walks down the steps of St Paul's Cathedral following a service for her 100th birthday. They are accompanied by Queen Elizabeth II, the Duke of Edinburgh, Prince Andrew and Princes Harry and William
Jonathan Evans/AFP
4 August 2000: Queen Elizabeth the Queen Mother celebrates her 100th birthday from the balcony of Buckingham Palace with her daughter the Queen
Ian Waldie/Getty Images
2 April 2002: The Queen rides her horse in the grounds of Windsor Castle, three days after the death of her mother
Dan Chung
9 April 2002: Her Majesty walks behind her mother's coffin following the Queen Mother's funeral at Westminster Abbey in London
Dan Chung/Reuters
4 June 2002: The Queen and the Duke of Edinburgh travel back to Buckingham Palace after the Golden Jubilee Service of Thanksgiving held at St Paul's Cathedral. Thousands of people gathered in central London for the festivities on the final day of the celebratory weekend marking the Queen's 50th year on the throne
Murray Sanders/Pool
14 January 2003: The Queen leaves King Edward VII hospital in London with a cane after undergoing surgery to remove torn cartilage from her right knee
Ian Waldie/Getty Images
13 December 2003: The Queen leaves London's King Edward VII hospital after undergoing surgery to remove skin lesions on her face and torn cartilage from her left knee. The knee operation had been announced in advance, but the removal of what Buckingham Palace described as "some minor benign skin lesions" from the Queen's face came as a surprise
Lee Besford/Reuters
7 May 2004: The Queen smiles during a visit to Heathrow Airport to mark the 10th anniversary of Unicef and British Airways' Change for Good programme
Chris Young/AFP
23 November 2004: The Queen and Prince Philip arrive for the state opening of Parliament in London
Ian Waldie/Getty Images
9 April 2005: The Prince of Wales and his new bride Camilla, Duchess of Cornwall, pose with Prince Harry, Prince William, Tom and Laura Parker Bowles, the Duke of Edinburgh, the Queen and Camilla's father Major Bruce Shand, in the White Drawing Room at Windsor Castle after their wedding ceremony
Hugo Burnand/Pool
14 May 2005: The Queen is reflected in the wing mirror of her Land Rover as she follows The Duke of Edinburgh as he competes in the Driving Grand Prix Competition at the Royal Windsor Horse Show
Julian Finney/Getty Images
12 April 2006: The Queen and Prince Harry smile during the Sovereign's Parade at the Royal Military Academy in Sandhurst
Dylan Martinez/Reuters
15 December 2006: The Queen looks up at a smiling Prince William during the Sovereign's Parade at the Royal Military Academy in Sandhurst
Dylan Martinez/Reuters
22 November 2006: The Queen receives a scroll from Bruce Two Dogs Bozsum, chairman of the Mohegan Tribal Council, at Southwark Cathedral in London
Stefan Rousseau
19 November 2007: The Queen and the Duke of Edinburgh walk at Broadlands in Romsey, southern England, as they prepare to celebrate their diamond wedding anniversary
Fiona Hanson/Pool
18 November 2009: Queen Elizabeth II leaves the Houses of Parliament after delivering her speech
Toby Melville/Reuters
7 December 2009: The Queen meets Lady Gaga following the Royal Variety Performance in Blackpool
Leon Neal/AFP
17 December 2009: The Queen boards a scheduled train at Kings Cross station in London to go to Kings Lynn in Norfolk for Christmas
Stefan Rousseau/Pool
27 April 2010: The Queen leaves Cymru Arena in Llandudno during a visit to North Wales
Chris Jackson/Getty Images
1 April 2011: The Queen arrives to visit her grandson, Prince William, at RAF Valley on Anglesey in north Wales, on a windy day
Phil Noble/Reuters
29 April 2011: Newly-weds Prince William and Kate Middleton kiss on the balcony at Buckingham Palace, watched by members of the royal family
Paul Gilham/Getty Images
24 May 2011: The Queen holds onto her hat in the wind as she speaks with US President Barack Obama at Buckingham Palace, during his two-day state  visit
Murray Sanders/Pool
3 June 2012: The Queen waves to the crowds from the Spirit of Chartwell during the Diamond Jubilee River Pageant on the River Thames. She is accompanied by Prince Philip, Camilla and Kate Middleton in a gilded royal barge leading an armada of 1,000 boats
John Stillwell/Pool
13 June 2012: Kate Middleton laughs as the Queen gestures while they watch part of a children's sports event during a visit to Vernon Park in Nottingham
Phil Noble/Reuters
24 July 2012: Her Majesty the Queen poses for a photograph with Prime Minister David Cameron and former Prime Ministers John Major, Tony Blair and Gordon Brown at 10 Downing Street where they had lunch to mark the Queen's Diamond Jubilee.
Stefan Rousseau/Pool
1 September 2012: Prince Philip, the Queen and Prince Charles cheer as competitors participate in a sack race at the Braemar Gathering in Scotland
Russell Cheyne/Reuters
20 June 2013: The Queen celebrates with members of her family and her racing team as her horse Estimate wins The Gold Cup at Royal Ascot
Darren Staples/Reuters
23 October 2013: The Queen looks on as Prince William and Kate Middleton carry Prince George for his christening at St James's Palace in London
John Stillwell/Pool
11 April 2014: The Queen reacts as Irish President Michael D Higgins and his wife Sabina prepare to leave Windsor Castle. Higgins was the first Irish president to make a state visit to Britain since independence
Leon Neal/AFP
24 June 2014: A youth takes a selfie in front of the Queen during her visit to St George's indoor market in Belfast, Northern Ireland
Peter Macdiarmid/Getty Images
17 July 2014: The Queen meets construction workers as she attends the official opening of the refurbished Reading Station
Ben Gurr/Reuters
16 October 2014: The Queen walks through a field of ceramic poppies that form part of "Blood Swept Lands and Seas of Red" at the Tower of London, an installation commemorating the centenary of World War I
Luke MacGregor/Reuters
4 June 2015: The Countess of Wessex, Princess Anne and members of the Women's Institute look on as the Queen cuts a cake celebrating the organisation's centenary at the Royal Albert Hall in London
Chris Jackson/Getty Images
18 May 2015: The Queen greets Prince Harry at the annual Chelsea Flower show in London
Julian Simmonds
27 May 2015: Queen Elizabeth II, accompanied by the Duke of Edinburgh and followed by the Prince of Wales and the Duchess of Cornwall, passes through the Royal Gallery during the State Opening of Parliament
Geoff Pugh
13 June 2015: The Queen is accompanied by Camilla, Prince Charles, Prince  William (holding Prince George), Kate Middleton and Prince Andrew on the  balcony at Buckingham Palace after the Trooping the Colour ceremony at Horse Guards Parade to honour the Queen's official birthday
Stefan Wermuth/Reuters
24 June 2015: Queen Elizabeth II attends a banquet in Berlin during her four-day State Visit to Germany
Michael Ukas
5 July 2015: Prince William and Kate Middleton talk to the Queen, Prince Phillip and Camilla as they arrive at the Church of St Mary Magdalene on the Sandringham Estate for the christening of Princess Charlotte
Chris Jackson/Getty Images
5 July 2015: Prince George talks to the Queen outside the Church of St Mary Magdalene on the Sandringham Estate for the christening of Princess Charlotte
Chris Jackson/Getty Images
9 September 2015: The Queen travels on a steam train to inaugurate the new Scottish Borders Railway on the day she became Britain's longest reigning monarch
Andrew Milligan
15 October 2015: The Queen chats to a guest at the new School of Veterinary Medicine at the University of Surrey in Guildford
Peter Nicholls
5 November 2015: The Queen looks at a display of medals during a visit to Imjin barracks in Innsworth, Gloucestershire
Richard Pohle
19 November 2015: The Queen is given a tour of a tram on the Metroline Tramline Extension in Birmingham
Chris Radburn
25 December 2015: The Queen attends a Christmas Day church service at Sandringham
Chris Jackson/Getty Images
23 February 2016: The Queen attends the formal unveiling of the new logo for Crossrail, which is to be named the Elizabeth line in her honour, at the construction site of Bond Street station
Richard Pohle
8 March 2016: The Queen smiles as she meets people being helped by the Prince's Trust at the Prince's Trust Centre in Kennington, London
Chris Jackson/Getty Images

The Queen will spend her actual birthday in Windsor, where she will meet and greet members of the public in a short walkabout near the castle. Her official birthday day will be marked in June, with a service of thanksgiving at Westminster Abbey, the Trooping The Colour parade and a giant street party on the Mall in front of Buckingham Palace for representatives of all the charities the Queen supports.