What will Harry wear on the big day?
Prince Harry is expected to don military uniform when he weds Meghan Markle.
His most senior military appointment is as Captain General of the Royal Marines - the ceremonial head of the Royal Marines.
He took over the role from his grandfather the Duke of Edinburgh following Philip's retirement.
The invitations for the royal wedding specified the dress code as "Uniform, Morning Coat or Lounge Suit, or Day Dress with Hat."
Harry is a former soldier who spent 10 years in the forces.
His Royal Marines uniform - the equivalent of a Field Marshal's - could follow that of Philip's when he carried out engagements as Captain General of the Royal Marines.
The Royal Marines of the Royal Navy are the UK's elite amphibious fighting force.
Harry will also wear his Army Air Corps wings above his Golden and Diamond Jubilee medals, and his Afghanistan Campaign medal.
For William and Kate's wedding, the prince, then a newly promoted captain in the Blues and Royals, wore a regal navy tunic, with gold wire shoulder chords, ornamental gold braiding and red and gold cuffs, but no sword.
It was the Blues and Royals' officer's uniform in dismounted review order, with a forage cap.
The Queen, who is head of the Armed Forces, will have the final say in what he wears.
Harry's brother William was told in no uncertain terms by his grandmother that he had to wear a red Guards' uniform on his wedding day because of his honorary title as Royal Colonel of the Irish Guards, rather than his RAF uniform.
Harry will not wear a blue sash across his uniform like William did because he is not yet a member of the Order of the Garter.
The prince also has two additional honorary RAF and Navy uniforms, because he was appointed Honorary Air Commandant of RAF Honington and Commodore-in-Chief of Small Ships and Diving.
The prince has also been seen in a white tunic - but this was his Blues and Royals' Tropical Weather Dress uniform.
Regiments and units that have a special relationship with the royal are taking part in the wedding.
The marriage ceremony will be enhanced by the spectacle of Household Cavalry troopers in their gleaming breast plates and plumed helmets lining the staircase at St George's Chapel, Windsor Castle, where the couple will marry on May 19.
Streets within the precincts of the castle will be lined by members of the Windsor Castle Guard from 1st Battalion Irish Guards, and by Armed Forces personnel from the Royal Navy Small Ships and Diving, Royal Marines, 3 Regiment Army Air Corps, The Royal Gurkha Rifles and RAF Honington.
Musical support to the street liners will be provided by the Band of the Irish Guards.