Traditional parades include November's Lord Mayor's Show, a centuries-old event celebrating the annual appointment of a new Lord Mayor of the City of London with a procession along the streets of the City, and June's Trooping the Colour, a formal military pageant performed by regiments of the Commonwealth and British armies to celebrate the Queen's Official Birthday.
Who participates in the military pageantry in the Trooping the Colour event every June?
regiments of the Commonwealth and British armies