The mounted officer's uniform features a scarlet jacket, a gold and crimson sash, gold sword slings (without an actual sword inside) and a forage cap. He will also wear the Garter Sash with the Wings of the Royal Air Force, the Garter Star and the Golden Jubilee Medal.
William, 28, is commissioned in all three armed services, but the Army's honorary Irish Guards position, which he earned in February, is his highest military title.
Prince Harry, meanwhile, will wear the uniform of Captain of the Household Cavalry (Blues and Royals). He will wear aiguillettes, a cross-belt and gold waist belt with sword slings, but no sword, and a forage cap. He will also wear the Wings of the Army Air Corps and Golden Jubilee and Afghanistan campaign medals.
William and Harry's father, Prince Charles, will wear the Royal Navy Number One Dress (Ceremonial). Charles has held the rank of Admiral of the Royal Navy since 2006.
Samir Hussein / Getty, Indigo / Getty