Britain's Queen Elizabeth and Prince Philip arrive for the fourth day of racing at Royal Ascot in southern England June 18, 2010. REUTERS/Stefan Wermuth
Britain's Queen Elizabeth talks with her grandson Prince William, watched by Prince Philip (R), after being shown around a Sea King search and rescue helicopter during a visit to RAF Valley, in north Wales April 1, 2011. Prince William, who is due to marry Kate Middleton on April 29, is serving as a search and rescue helicopter pilot, based at RAF Valley on Anglesey, an island off the north west coast of Wales. REUTERS/Christopher Furlong/Pool
Britain's Queen Elizabeth addresses both Houses of Parliament, next to her husband Prince Philip at Westminster Hall in London March 20, 2012. REUTERS/Ben Stansall/POOL
Britain's Queen Elizabeth (C), Prince Philip (R), and Prince William, walk amongst spring blossom and flowers as they arrive to attend the unveiling of the Windsor Greys statue in Windsor southern England March 31, 2014. The statue marks sixty years of Queen Elizabeth's Coronation in 2013 and the important role played by Windsor Greys in the ceremonial life of Britain's royal family. REUTERS/Toby Melville
Britain's Queen Elizabeth waits to read the Queen's Speech to lawmakers in the House of Lords, next to Prince Philip, during the State Opening of Parliament in central London May 9, 2012. REUTERS/Oli Scarff/POOL
Britain's Queen Elizabeth (R), Prince Philip (2nd R), and Olympic torch bearer Gina Macgregor (2nd L) watch as torchbearer Phil Wells takes the Olympic Flame at Windsor Castle, west of London July 10, 2012. REUTERS/Ben Stansall/Pool
Britain's Queen Elizabeth (L) and Prince Philip visit Burnley College and University of Central Lancashire in northern England May 16, 2012. The Queen and the Prince are on a two-day visit to northwest England. REUTERS/Paul Grover/Pool
Britain's Queen Elizabeth and Prince Philip, Duke of Edinburgh, arrive to attend the fifth day of racing at the Royal Ascot, southwest of London June 23, 2012. REUTERS/Stefan Wermuth
Britain's Queen Elizabeth is accompanied by Prince Philip as they proceed through the Royal Gallery before the State Opening of Parliament in the House of Lords, at the Palace of Westminster in London Britain May 27, 2015. REUTERS/Suzanne Plunkett - RTX1EQQD
The Queen Elizabeth II, Prince Philip and David Webster are talking with Margot Fonteyn at CG Gala June 10, 1958. REUTERS/Stringer BEST QUALITY AVAILABLE - RTX5E1
A man arrives with birthday balloons and flowers at the London Clinic in London June 10, 2013. Britain's Prince Philip is recovering after an operation at the hospital and celebrates his 92nd birthday today. REUTERS/Luke MacGregor
Britain's Prince Philip, Duke of Edinburgh, who is the Chancellor of the University of Edinburgh, wears his ceremonial gown as he watches the installation ceremony of the university's new rector Ian Macwhirter in Edinburgh, Scotland March 10, 2009. The traditional 'Chairing of the Rector' parade involves students carrying the new Rector shoulder-high on a Sedan chair around Old College grounds. REUTERS/David Moir
Britain's Queen Elizabeth and her husband Prince Philip leave the Houses of Parliament following the annual State Opening of Parliament in London, November 18, 2009. REUTERS/Toby Melville
Britain's Prince Charles (2nd L) greets his father Prince Philip, watched by his wife, Camilla, Duchess of Cornwall (R) and his son Prince Harry (3rd R), during a visit to Prince Harry's Sentebale 'Forget-Me-Not' garden, representing his Sentebale charity, at the Chelsea Flower Show in central London May 20, 2013. The annual show opens to the public on Tuesday. REUTERS/Geoff Pugh/Pool
Britain's Prince Philip (R) listens as his wife Queen Elizabeth speaks during her address to the House of Lords, at the State Opening of Parliament in Westminster, London May 25, 2010. The new British coalition government set out its legislative agenda on Tuesday in a speech delivered by Queen Elizabeth at the state opening of parliament. REUTERS/Leon Neal/Pool
Britain's Queen Elizabeth and her husband Prince Philip attend a Maundy Service on her 85th birthday at Westminster Abbey in London April 21, 2011. REUTERS/Arthur Edwards/Pool
Britain's Queen Elizabeth addresses both Houses of Parliament, next to her husband Prince Philip at Westminster Hall in London March 20, 2012. REUTERS/Jack Hill/POOL
Britain's Queen Elizabeth and Prince Philip laugh after bidding farewell to the President of Ireland Michael D. Higgins and his wife Sabina at Windsor Castle in Windsor, southern England April 11, 2014. The Irish President and his wife Sabina left Windsor at the end of a four day State Visit to Britain, during which they stayed at Windsor Castle as guests of Queen Elizabeth. REUTERS/Leon Neal/Pool
Britain's Queen Elizabeth and Prince Philip view the horses from the parade ring before the Diamond Jubilee Coronation Cup race at the Epsom Derby festival in Epsom, southwest of London June 2, 2012. Queen Elizabeth gets four days of celebrations to mark her 60 years on the British throne under way on Saturday with one of her favourite pastimes, a trip to the horse races, as tributes to the long-serving monarch pour in. REUTERS/Ben Stansall/pool
Britain's Prince Philip, the Duke of Edinburgh (L) meets Ian "Spike" Betterton, Chair of The Friends of St Georges Park, during a visit to Kidderminster in central England July 11, 2012. Prince Philip was accompanying Britain's Queen Elizabeth during her nationwide Diamond Jubilee tour. REUTERS/Heathcliffe O'Malley/Pool
Britain's Queen Elizabeth arrives with Prince Philip (R) at the Diamond Jubilee Pageant in Windsor, Berkshire May 13, 2012. REUTERS/Jane Mingay/Pool
Britain's Queen Elizabeth, Prince Philip and Prince Charles (R) watch the sack race at the annual Braemar Highland Gathering in Braemar, Scotland, Britain September 5, 2015. Queen Elizabeth will become Britain's longest-ever serving monarch on September 9. REUTERS/Russell Cheyne TPX IMAGES OF THE DAY - RTX1R92L
Britain's Prince Philip (L) leaves after presenting Royal Medals at the Royal Society of Edinburgh, in Edinburgh August 12, 2013. The Prince, making his first public appearance since his hospital admission in June, presented the Royal Medals which are awarded for a range of subjects. REUTERS/Andrew Milligan/Pool
Britain's Queen Elizabeth (C) and Wanda Henton Brown, the wife of Bermuda Premier Ewart Brown, wait for the beginning of the receiving line as Prince Philip (L) looks out of a window prior to a state dinner in Bermuda November 25, 2009. The Queen's three-day visit is in conjunction with the 400th anniversary of settlement on the island. REUTERS/Hans Deryk
Britain's Queen Elizabeth (L) and Prince Philip arrive for Ladies Day on the third day of the Royal Ascot horse racing meet June 21, 2007.REUTERS/Toby Melville
Britain's Queen Elizabeth gestures beside her husband Prince Philip before the 151st running of the Queen's Plate horse race in Toronto July 4, 2010. REUTERS/Fred Thornhill
Britain's Prince Philip arrives on the eve of his 90th birthday to take the salute of the Household Division Beating Retreat on Horse Guards Parade in London June 9, 2011. REUTERS/Paul Edwards/Pool
Britain's Prince Philip the husband of Queen Elizabeth, leaves after the Commonwealth Day Observance service at Westminster Abbey in central London March 11, 2013. The Queen, who is the head of the Commonwealth, pulled out of attending the service as she continues to recover from a recent illness. REUTERS/Matt Dunham/Pool
Prince Philip, Duke of Edinburgh pauses during his visit to the 'Neues Museum' in Berlin November 3, 2004. Queen Elizabeth, hoping to further reconciliation between Britain and Germany, urged the two former World War Two foes to learn from history but not be obsessed by the past and to reject national stereotypes. REUTERS/Tobias Schwarz TOB/JOH - RTR15C49
Britain's Prince Philip waves to members of the media as he leaves the King Edward VII Hospital in London June 9, 2012. The husband of Britain's Queen Elizabeth left hospital on the eve of his 91st birthday on Saturday, five days after he was taken ill during celebrations to mark the monarch's 60 years on the throne. REUTERS/Paul Hackett
Britain's Queen Elizabeth visits the ArcelorMittal Orbit tower with Prince Philip (R) in London July 28, 2012. REUTERS/Neil Hall
Members of Britain's Royal Family, Prince Charles (2L), Prince Philip (3L), Commodore Tim Laurence (C), Prince Harry (4R), the Earl of Wessex (3R), Princess Anne (2R) and Prince Andrew (R) arrive at St Mary Magdalene church on the Sandringham estate in Norfolk, December 25, 2003. Britain's Queen Elizabeth made her first public appearance since undergoing knee surgery on Christmas Day, arriving at the traditional family church service by car. REUTERS/Toby Melville TM/ASA/GM - RTR99Y4
Britain's Prince Philip officially opens the new Cellarium Cafe at Westminster Abbey in central London October 17, 2012 . REUTERS/Oli Scarff/Pool
Britain's Queen Elizabeth leaves with Prince Philip after a service of thanksgiving for her 90th birthday at St Paul's Cathedral in London, Britain, June 10, 2016. REUTERS/Peter Nicholls TPX IMAGES OF THE DAY - RTSGW9X
Britain's Queen Elizabeth and Prince Philip attend a service celebrating the 60th anniversary of the Queen's coronation at Westminster Abbey in London June 4, 2013. Britain's Queen Elizabeth returned to the scene of her coronation on Tuesday to mark a reign that has weathered six decades of social transformation and the end of her country's global empire. REUTERS/Jack Hill/Pool
Britain's Queen Elizabeth and Prince Philip, the Duke of Edinburgh walk at Broadlands in Romsey, southern England in this undated photograph taken in 2007. The Queen and Prince Philip will mark their diamond wedding anniversary with a special service of thanksgiving on November 19, 2007. REUTERS/Fiona Hanson/Pool
His Royal Highness Prince Philip, Duke of Edinburgh entrusts new regimental colours to Lieutenant Bronson Peacock from 3rd Battalion of The Royal Canadian Regiment at a Queen's Park ceremony in Toronto April 27, 2013. The Duke of Edinburgh has been the Colonel-in Chief of the Royal Canadian Regiment since 1953. REUTERS/Fred Thornhill
A Royal Collection handout photograph shows Princess Elizabeth and The Duke of Edinburgh walking in the grounds of Broadlands in southern England, the home of the Duke's uncle, Earl Mountbatten on their honeymoon, November 1947. Queen Elizabeth and Prince Philip will mark their diamond wedding anniversary with a special service of thanksgiving on November 19, 2007. REUTERS/The Royal Collection/Handout
Britain's Prince Phillip, the Duke of Edinburgh, is greeted during a visit to the British Garden at Hanover Square in New York July 6, 2010. The British Garden is a memorial to British citizens who died at the World Trade Center on September 11, 2001. REUTERS/Henny Ray Abrams/Pool
Britain's Prince Philip smiles during his visit with Queen Elizabeth to the Irish National Stud in Kildare, Ireland May 19, 2011. The Queen is on the third day of a four day state visit to Ireland which is the first state visit by a British monarch since Ireland's independence. REUTERS/Dylan Martinez
Britain's Prince Philip attends a service at the Field of Remembrance at Westminster Abbey in London November 8, 2012. REUTERS/Olivia Harris
Image used for illustrative purposes. The hand of Britain's Queen Elizabeth II (L) is held by her husband, Prince Philip, Duke of Edinburgh, after her speech at the State Opening of Parliament in the House of Lords in London, November 13, 2002. REUTERS/Russell Boyce
Britain's Queen Elizabeth (R) and Prince Philip, The Duke of Edinburgh, view horses in the parade ring at the Epsom Derby festival, part of the Queen's Diamond Jubilee celebrations, in Epsom, southwest of London June 2, 2012. Queen Elizabeth gets four days of celebrations to mark her 60 years on the British throne under way on Saturday with one of her favourite pastimes, a trip to the horse races, as tributes to the long-serving monarch pour in. REUTERS/Toby Melville
Britain's Queen Elizabeth (C) and Prince Philip (centre 2nd R) arrive at the opening ceremony as International Olympic Committee (IOC) President Jacques Rogge (centre 2nd L), wife of British Prime Minister David Cameron, Samantha Cameron (front 2nd R), and other members of the audience applaud at the London 2012 Olympic Games at the Olympic Stadium July 27, 2012. REUTERS/Mike Blake
Britain's Duke of Edinburgh samples a glass of 'Jubilee ale' at the
Bass Museum in Burton upon Trent in Staffordshire July 3, 2002. Prince
Philip, along with his wife Britain's Queen Elizabeth II, visited the
area on the second day of their Golden Jubilee tour of the West
Midlands. REUTERS/Michael Dunlea/POOL
NMB - RTR75O9
Britain's Queen Elizabeth receives the trophy from Prince Philip, Duke of Edinburgh, after her horse Estimate won The Queen's Vase on the fourth day at Royal Ascot, southwest of London June 22, 2012. REUTERS/Stefan Wermuth
Members of the royal family, including Prince Charles, Catherine, Duchess of Cambridge holding Princess Charlotte, Prince George, Prince William, Queen Elizabeth, and Prince Philip watch a flypast as they stand on the balcony of Buckingham Palace after the annual Trooping the Colour ceremony on Horseguards Parade in central London, Britain June 11, 2016. Trooping the Colour is a ceremony to honour Queen Elizabeth's official birthday. The Queen celebrates her 90th birthday this year. REUTERS/Toby Melville - RTX2FN4F
Britain's Prince Philip (C) smiles after presenting Royal Medals at the Royal Society of Edinburgh, in Edinburgh August 12, 2013. The Prince, making his first public appearance since his hospital admission in June, presented the Royal Medals which are awarded for a range of subjects. REUTERS/Andrew Milligan/Pool
Britain's Prince Philip, Duke of Edinburgh attends the Epsom Derby in Epsom, south of London, June 1, 2013. REUTERS/Andrew Winning
Britain's Prince Philip takes part in a ceremonial welcome for United Arab Emirates President Sheikh Khalifa bin Zayed bin Sultan Al Nahyan during his state visit at Windsor Castle, in Windsor, southern England April 30, 2013. REUTERS/Toby Melville
Britain's Queen Elizabeth (L) watches a performer with Prince Philip (C) and Laureen Harper, wife of Canada's Prime Minister Stephen Harper, during Canada Day celebrations on Parliament Hill in Ottawa July 1, 2010. REUTERS/Chris Wattie
Britain's Queen Elizabeth II and the Duke of Edinburgh view the restored bed-chamber at the Maritime Museum in London, in this May 1, 1990 file photo. The Queen reopened the Queen's house at the Museum which has recently been refurbished at a cost of five million pounds sterling. REUTERS/Mike Parsson - RTR1EDXU
Britain's Queen Elizabeth (R) applies lipstick as she sits next to her husband Prince Phillip during the Braemar Royal Highland Gathering in Scotland September 3, 2011. REUTERS/David Moir
Britain's Queen Elizabeth and Prince Philip wave from the balcony of Buckingham Palace after attending the Trooping the Colour ceremony in London June 13, 2009. Trooping the Colour has honoured the sovereign's official birthday since the 17th century, and dates back to the earliest times of armed conflict when each leader needed his own flag or colours to stand out clearly amid the smoke and dust of battle, which led to regular trooping allowing soldiers to recognise the colours around which they should rally. REUTERS/Kieran Doherty
Members of Britain's Royal family (L-R) Prince Charles, Prince Edward, Queen Elizabeth, Princess Anne, Prince Philip, Tim Lawrence, Louise Windsor, Catherine, Duchess of Cambridge and Prince William, watch a flypast by the Red Arrows as they stand on the balcony of Buckingham Palace following the Trooping the Colour ceremony in central London June 16, 2012. Trooping the Colour is a ceremony to honour the sovereign's official birthday. REUTERS/Toby Melville
Britain's Prince Philip and Princess Anne attend the equestrian Eventing Individual Dressage Day 2 in the Greenwich Park during the London 2012 Olympic Games, July 29, 2012. REUTERS/Mike Hutchings
QUEEN ELIZABETH AND PRINCE PHILIP LOOK AROUND OMAGH BOMB SCENE DURING
GOLDEN JUBILEE VISIT TO NORTHERN IRELAND.
Britain's Queen Elizabeth (L) and Prince Philip pause during their tour
around Market street in Omagh, County Tyrone, Northern Ireland, May 14,
2002. Market Street was the site of a Real IRA bombing in August 1998
which claimed 29 lives, the largest single loss of life during the
troubles. REUTERS/Paul McErlane - RTR5488
Britain's Prince Philip leaves after a service of thanksgiving for Queen Elizabeth's 90th birthday at St Paul's Cathedral in London, Britain, June 10, 2016. REUTERS/Ben Stansall/Pool - RTSGWC2
Britain's Queen Elizabeth presents her husband Prince Philip with New Zealand's highest honour, the Order of New Zealand at Buckingham Palace in London June 6, 2013. Prince Philip celebrates his 92nd birthday on June 10. REUTERS/Anthony Devlin/POOL
Britain's Prince Philip's signature is seen after he signed the book of condolence for victims of the Australian bushfires at the Australian High Commission in London February 17, 2009. The death toll in Australia's deadliest bushfires reached 200 yesterday as police continued to search through ash and rubble of several razed towns in the southern state of Victoria. Photo taken February 17, 2009. REUTERS/Dominic Lipinski/Pool
Paygan Russell (2nd R), daughter of British Military Policeman Russell Aston who was killed in Afghanistan, gestures as she meets Britain's Prince Philip at the Field of Remembrance at Westminster Abbey in London November 5, 2009. REUTERS/Alastair Grant/Pool
Paraguayan dictator Alfredo Stroessner (R) rides with Britain's Prince Philip, the Duke of Edinburgh, during a visit by the Prince in downtown Asuncion, Paraguay, in this 1963 file photo. Former Paraguayan dictator Stroessner died on August 16, 2006 at a hospital in the Brazilian capital Brasilia, where he has lived in exile since being toppled in a 1989 military coup, the hospital said. REUTERS/R. E. Adorno/Files
Prince Philip, Duke of Edinburgh looks up after Britain's Queen Elizabeth (not pictured) dedicated a wreath of flowers at the site of the September 11, 2001 World Trade Center attack during her visit to New York July 6, 2010. REUTERS/Lucas Jackson
Britain's Prince Phillip arrives for the wedding of Zara Phillips, the eldest granddaughter of Queen Elizabeth, and England rugby captain Mike Tindall, at Canongate Kirk in Edinburgh, Scotland July 30, 2011. REUTERS/Nigel Roddis
Britain's Queen Elizabeth and Prince Philip wait to greet guests prior to a state banquet at Bellevue presidential palace in Berlin, Germany June 24, 2015. Queen Elizabeth and the Duke of Edinburgh are on a three day state visit to Germany. REUTERS/Wolfgang Kumm/Pool TPX IMAGES OF THE DAY - RTR4YT5D
Britain's Queen Elizabeth (L) and her husband Prince Philip watch from the forecourt of Buckingham Palace during the Trooping the Colour ceremony in central London June 16, 2012. Trooping the Colour is a ceremony to honour the sovereign's official birthday. REUTERS/Toby Melville
Britain's Prince Philip visits the Aquatics Centre with Princess Anne in London July 28, 2012. REUTERS/Neil Hall
Britain's Prince Philip (C) talks to Prince Charles (L), Prince William (2nd R) and Prince Harry on the Spirit of Chartwell during the Diamond Jubilee River Pageant on the River Thames, in London June 3, 2012. Queen Elizabeth joined an armada of 1,000 boats in a gilded royal barge, in a pageant down the River Thames on Sunday in a spectacular highlight of four days of nationwide celebrations to mark her Diamond Jubilee. REUTERS/John Stillwell/Pool
Britain's Queen Elizabeth speaks to her husband Prince Philip as they attend the official re-opening of the Cutty Sark in Greenwich, London April 25, 2012. The Cutty Sark is the world's last surviving tea clipper and has been extensively restored after being damaged by fire in 2006. REUTERS/Paul Hackett
Britain's Queen Elizabeth travels with Prince Philip on the new Scottish Borders railway line, in Scotland, September 9, 2015. Queen Elizabeth officialy opened the new Scottish Borders Railway on the day she became Britain's longest reigning monarch. REUTERS/Andrew Milligan/Pool - RTSCW8
A pigeon flies ahead of Britain's Queen Elizabeth and Prince Philip, and Princes William, Harry and Kate Duchess of Cambridge behind as they wave to guests attending the Patron's Lunch on the Mall, an event to mark her 90th birthday, in London, June 12, 2016. REUTERS/Toby Melville TPX IMAGES OF THE DAY - RTX2FRL7
Britain's Prince Philip looks at a display before presenting Royal Medals at the Royal Society of Edinburgh, in Edinburgh August 12, 2013. The Prince, making his first public appearance since his hospital admission in June, presented the Royal Medals which are awarded for a range of subjects. REUTERS/Andrew Milligan
Britain's Prince Philip waits to greet India's President Pratibha Patil in Windsor, southern England, October 27, 2009. Patil, the first woman to serve as President of India will stay at Windsor castle during her three-day state visit as a guest of Britain's Queen Elizabeth. REUTERS/Toby Melville
Britain's Queen Elizabeth (L) and Prince Philip (R) leave after the State Opening of Parliament, at the Palace of Westminster in London May 8, 2013. REUTERS/Kirsty Wigglesworth/Pool
Prince Philip to retire from public engagements: Buckingham Palace
Recent and archive images of Britain’s Prince Philip, Queen Elizabeth’s husband.