He is a colonel in the Irish Guards and that is the uniform he wore for his wedding.
He also hold rank in other units of the service but not as high.
Cornet .
They are of the same rank but Prince Charles' wife will become queen beofre Prince William's wife.
Prince William holds the rank of Captain in the Blues and Royals, Lieutenant in the Royal Navy and Flight Lieutenant in the Royal Air Force.
Prince Harry is a newly promoted Captain in the Household Cavalry's Blues and Royals.
William Wales
Because he is the son of the HRH the Prince of Wales he uses the name Prince William of Wales.
His Military Dress uniform.
The Duke of Cambridge, however, whereas Catherine is the Duchess of Cambridge, rather than a Princess, William retains his rank as Prince. He is therefore Prince William, Duke of Cambridge.
His uniform as an honorary military officer.
Yes, its like how sergeant is a higher rank than corporal in military ranks.
It's complicated.The Queen has stipulated that all her male descendants who do not bear the titular dignity of Prince shall use Mountbatten-Windsor as their surname.Willam and Harry, though, DO "bear the titular dignity of Prince".For these cases, children generally use "Prince X of Y" where X is their given name and Y is their father's territorial designation. For William and Harry, their father is Prince Charles, who is the Prince of Wales, so they were "Prince William of Wales" and "Prince Harry of Wales".This is normally dropped when such children reach adulthood and simply use their title. You need a last name when you might get confused with someone else. The likelihood of, say, Prince William, Duke of Cambridge getting confused with some other Prince William, Duke of Cambridge is pretty small.However: William and Harry were both in the military, and not having a surname in the military is a little awkward. Both of them used "Wales" as their surname in a military context. William (as Duke of Cambridge) now has his own territorial designation; I'm not sure if he's been updated officially to "William Cambridge" in the military or not.
My guess would be "Prince". Actually, it would be Queen since Queen Elizabeth was in attendance.