The oldest uniforms in the parade will, logically, be those of the Old Guard, the nickname given to the 3rd Infantry Regiment ...

King Charles led a moment of silence and changed his uniform to pay tribute at the centuries-old Trooping the Colour parade.

Soldiers will wear period costumes from wars throughout U.S. history to march in the Army parade. 'It's a little hot, but we'll get used to it,' one said.