Prince Philip: 1921 - 2021

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. REUTERS/Mike Parsson

Queen Elizabeth and Prince Philip, wearing the uniform of the Honorary Colonel-in-Chief of the Royal Canadian Regiment, pose for a portrait at Buckingham Palace in 1959.   Library and Archives Canada/National Film Board of Canada

Queen Elizabeth and Prince Philip pose for a portrait at Buckingham Palace in 1952.  Library and Archives Canada/National Film Board of Canada

Prince Philip leaves after a service of thanksgiving for Queen Elizabeth's 90th birthday at St Paul's Cathedral in London, June 10, 2016. REUTERS/Ben Stansall/Pool

Britain's Queen Elizabeth and Prince Philip, the Duke of Edinburgh walk at Broadlands in Romsey, southern Englandin 2007. After a year long courtship, the Queen and Prince Philip wed in November 20, 1947, at Westminster Abbey. REUTERS/Fiona...more

Prince Charles with his sons Prince William and Prince Harry, his father the Duke of Edinburgh and Earl Spencer the brother of Diana, Princess of Wales walk to join the funeral cortege bearing the coffin of Princess Diana to Westminster Abbey,...more

Queen Elizabeth and Prince Philip pose with U.S. President John F. Kennedy and First Lady Jacqueline Kennedy at Buckingham Palace in London, June 5, 1961. John F. Kennedy Presidential Library and Museum/via REUTERS

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

Prince Philip sits with the Queen as she delivers her speech in the House of Lords, during the State Opening of Parliament at the Palace of Westminster in London June 4, 2014. REUTERS/Carl Court/Pool

Britain's Queen Elizabeth and her husband Prince Philip pause during a tour of the Royal London Hospital in east London on February 27, 2013. REUTERS/Ian Gavan/Pool

Prince William, Duke of Cambridge, Catherine, Duchess of Cambridge, Prince Philip, Duke of Edinburgh and Queen Elizabeth II arrive to greet guests attending a garden party at Buckingham Palace, May 24, 2016.  REUTERS/Dan Kitwood/Pool

Britain's Queen Elizabeth and Prince Philip take a boat trip on Spree river in Berlin, Germany June 24, 2015. REUTERS/Hannibal Hanschke

U.S. First Lady Betty Ford and Prince Philip dance during the state dinner in honor of Queen Elizabeth and Prince Philip at the White House, July 7, 1976. Ricardo Thomas/Gerald R. Ford Library

Prince Philip talks with one of the riders after horses from a local ranch were ridden down to the station to form a Guard of Honor during the visit of Queen Elizabeth and Prince Philip to Kamloops, British Columbia, Canada in July 1959.  Gar...more

U.S. President Richard Nixon, Queen Elizabeth and Prince Philip tour the Marble Hall in Buckingham Palace in London, February 1969.  Richard Nixon Presidential Library/via REUTERS

Queen Elizabeth, Prince Philip and David Webster talk with ballerina Margot Fonteyn in London, June 10, 1958. REUTERS/Stringer

Prince Philip pauses in front of a life-sized cartoon of himself at the opening of New Zealand cartoonist Sir David Low's exhibition at the National Library in Wellington, November 7, 1995. REUTERS/Stringer

Prince Philip, in his role as the Regiment Colonel in Chief, visits The Queens Royal Hussars in Basra, Iraq, October 2006. REUTERS/Ministry of Defence

Prince Philip wears the uniform of the Honorary Colonel-in-Chief of the Royal Canadian Regiment as he poses for a portrait at Buckingham Palace in 1959.  Library and Archives Canada/National Film Board of Canada

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.   REUTERS/Leon Neal/Pool

Prince Philip offers a helping hand to the Queen Mother as they leave church following morning service at the Saint Mary Magdalene church in Sandringham, December 25, 1999. REUTERS/Dylan Martinez

Queen Elizabeth and Prince Philip watch as an orphan performs at the Mildmay HIV Centre in Kampala, Uganda, November 22, 2007. REUTERS/Jon Hrusa/Pool

Prince Philip sips from a glass of Boag beer as he visits the brewery in Launceston, Australia, March 29, 2000. REUTERS/Russell Boyce

A pigeon flies ahead of Queen Elizabeth and Prince Philip, and Princes William, Harry and Catherine, 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,...more

Queen Elizabeth and Prince Philip wait to greet guests prior to a state banquet at Bellevue presidential palace in Berlin, Germany June 24, 2015. REUTERS/Wolfgang Kumm/Pool

Prince Philip entrusts new regimental colours to Lieutenant Bronson Peacock from 3rd Battalion of The Royal Canadian Regiment at a Queen's Park ceremony in Toronto, Canada April 27, 2013. REUTERS/Fred Thornhill

Prince William and his bride Catherine, Duchess of Cambridge pose for an official photograph with their families, on the day of their wedding, in the throne room at Buckingham Palace, in central London April 29, 2011.   REUTERS/Hugo Burnand/Clarence...more

Queen Elizabeth stands with her husband Prince Philip, son Prince Charles and grandsons William and Harry during the unveiling of a memorial fountain dedicated to the late Princess Diana at Hyde Park in London, July 6, 2004. REUTERS/David Bebber

Britain's Queen Elizabeth (R) and Prince Philip (L) talk at the annual Braemar Highland Gathering in Braemar, Scotland September 6, 2014. REUTERS/Russell Cheyne

Queen Elizabeth, Prince Philip, Prince Harry, Prince William, the Duke of Cambridge and his wife, Catherine, the Duchess of Cambridge share a light moment as they stand on the balcony of Buckingham Palace in the annual Trooping of the Colour ceremony...more

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. REUTERS/Anthony Devlin/POOL

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. REUTERS/Toby Melville

Members of Britain's royal family (front L-R) Prince Philip and Queen Elizabeth cheer as competitors participate in a sack race at the Braemar Gathering in Braemar, Scotland September 1, 2012. REUTERS/Russell Cheyne

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

Britain's Queen Elizabeth smiles as she 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

The Duchess of Cornwall, the Prince of Wales, Queen Elizabeth II, the Duke of Edinburgh, and Duke and Duchess of Cambridge (L-R) arrive for the annual evening reception for members of the Diplomatic Corps at Buckingham Palace in London, Britain...more

Queen Elizabeth II and Prince Philip share a moment as they attend the Beating the Retreat ceremony on Horseguards Parade, June 12 1996. REUTERS/Stringer

Queen Elizabeth travels with Prince Philip on the new Scottish Borders railway line, in Scotland, September 9, 2015. REUTERS/Andrew Milligan/Pool

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 Prince Philip, in his role as Captain General, Royal Marines, attends a Parade to mark the finale of the 1664 Global Challenge, on the Buckingham Palace Forecourt in London, August 2, 2017. It was his final solo appearance at an official...more