Prince Philip to step down from royal duties

1. Prince Philip to step down from royal duties

2. 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

3. 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

4. Britain's Prince Philip leaves Buckingham Palace in London, May 4, 2017. REUTERS/Neil Hall

5. Queen Elizabeth addresses both Houses of Parliament, next to Prince Philip at Westminster Hall in London March 20, 2012. REUTERS/Jack Hill/Pool

6. The hand of Queen Elizabeth is held by Prince Philip after her speech at the State Opening of Parliament in the House of Lords in London, November 13, 2002. REUTERS/Russell Boyce

7. Queen Elizabeth and Prince Philip view the restored bed-chamber at the Maritime Museum in London, May 1, 1990. REUTERS/Mike Parsson

8. 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. REUTERS/The Royal Collection

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

10. 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

11. 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

12. The Duke of Edinburgh attends the Colonel's Review ceremony at Horse Guards Parade in London, June 5, 2004. REUTERS/Toby Melville

13. 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

14. 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

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

16. The Duke of Edinburgh listens to residents during a garden party at Hillsborough Castle, County Down in Northern Ireland, July 30, 2001. REUTERS/File

17. Queen Elizabeth and Prince Philip attend the Beating the Retreat ceremony on Horseguards Parade, June 13, 1996. REUTERS/File

18. Queen Elizabeth and Prince Philip walk at Broadlands in Romsey, southern England, November 2007. REUTERS/Fiona Hanson/Pool

19. 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

20. 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

21. 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,

22. 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

23. Queen Elizabeth, Prince Philip and Prince Charles watch the sack race at the annual Braemar Highland Gathering in Braemar, Scotland, Britain September 5, 2015. REUTERS/Russell Cheyne

24. Prince Philip meets Ian "Spike" Betterton, Chair of The Friends of St Georges Park, during a visit to Kidderminster in central England July 11, 2012. REUTERS/Heathcliffe O'Malley/Pool

25. Queen Elizabeth talks with her grandson Prince William, watched by Prince Philip, after being shown around a Sea King search and rescue helicopter during a visit to RAF Valley, in north Wales April 1, 2011.

26. 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

27. Prince Philip smiles after presenting Royal Medals at the Royal Society of Edinburgh, in Edinburgh August 12, 2013. REUTERS/Andrew Milligan/Pool

28. 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

29. Queen Elizabeth, Prince Philip and Prince William walk amongst spring blossom and flowers in Windsor, southern England March 31, 2014. REUTERS/Toby Melville

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

31. 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

32. Queen Elizabeth and Prince Philip arrive for the fourth day of racing at Royal Ascot in southern England, June 18, 2010. REUTERS/Stefan Wermuth