What William's wearing on his wedding day

London (CNN) -- Who'll be making a fashion statement at the royal wedding of the century? Not Prince William.

Following tradition, William, along with his dad and brother, are wearing military uniforms to the ceremony at Westminster Abbey, according to St. James's Palace.

William is wearing an Irish Guards uniform, which is known for its bright red coat. Specifically, he'll wear the uniform of Colonel of the Irish Guards, reflecting his senior honorary appointment in the Army.

In pageantry befitting the heir to the British throne, he'll also don a gold and crimson sash featuring gold sword slings. However, he won't carry a sword.

His red coat will feature buttons in groups of four, which symbolize the Irish Guards' position in the Order of Battle as the Fourth Regiment of Foot Guards.

Whether his bride Kate Middleton will wear a tiara when she walks down the aisle remains under wraps, but there's no mystery surrounding William's head dress.

The palace has revealed that he will wear a so-called forage cap, which is worn by members of the Army for dress occasions.

The cap carries the insignia of the Irish Guards, the eight-pointed Star of the Most Illustrious Order of St. Patrick, and features the regiment's motto, "Quis Separabit?", which means "Who shall separate us?"

William, a graduate of Britain's royal military academy Sandhurst, was appointed Colonel of the Irish Guards in February. He also has honorary ranks in the Royal Navy and Royal Air Force.

His brother Prince Harry, who is his best man and in charge of carrying the wedding ring to the Abbey, is also sporting a military uniform and forage cap.

Harry's wearing a Blues and Royals officer's uniform. The Blues and Royals is one of the oldest regiments in the British Army and is part of the Household Calvary.

Harry's uniform will feature ornamental braiding, a cross-belt and a gold waist belt with sword slings. Like his brother, he won't carry a sword.

Prince Charles, an Admiral of the Royal Navy since 2006, is wearing the Royal Navy Number One Dress, the formal uniform worn for ceremonial purposes.

The Prince of Wales will be decked out in a blue sash featuring a bevy of badges and no fewer than six medals. Unlike William and Harry, he will carry a sword.