Royal Horse Artillery

LONDON, ENGLAND - APRIL 22:  Members of the King's Troop Royal Horse Artillery fire a 41-gun royal salute in Green Park to celebrate Queen Elizabeth II's 87th birthday on April 22, 2013 in London, England. Gun salutes in honour of the Queen's birthday have been postponed by one day this year as her actual birthday, which is on April 21st, fell on a Sunday.

Oli Scarff/Getty

Members of the King’s Troop Royal Horse Artillery fire a 41-gun royal salute in Green Park to celebrate Queen Elizabeth II’s 87th birthday (April 22) in London, England. Gun salutes in honour of the Queen’s birthday have been postponed by one day this year as her actual birthday fell on a Sunday.