Gun salutes are used as a sign of respect or welcome, both at sea and onshore, though are mostly used on special occasions, often with a Royal link. The firing of a canon used to display friendly intentions, much like the traditional salute revealed an unarmed stranger. Royal salutes are regularly given in London, and are always given to celebrate Accession Day (6th February), The Queen’s birthday (21st April), Coronation Day (2nd June), The Queen’s official birthday (a Saturday in June), The Duke of Edinburgh’s birthday (10th June), Prince Charles’ birthday (14th November), and at the State Opening of Parliament in May. Royal births, the prorogation of Parliament, and the meeting of a Head of State with the Sovereign in London, Windsor or Edinburgh are all marked with gun salutes.
Hyde Park and the Tower of London are two locations regularly used for such salutes, but the number of rounds fired are different: a standard Royal gun salute is 21 rounds. Since Hyde Park is a Royal park, it fires another 40. The Tower has an extra 41 on Royal birthdays and anniversaries– 20 because it is a Royal Palace and Fortress, and 21 because it is located within the City of London, and just 41 for other occasions. The salute is fired by the Honourable Artillery Company at 1.00 pm at the Tower. It is thought the Tower of London holds the record for the most rounds fired in a single salute: 124 rounds were fired on 10th June 2006, as it was The Queen’s official birthday, giving need for 62 rounds, as well as The Duke of Edinburgh’s birthday, another 62 rounds.
Other locations are sometimes authorised to fire gun salutes across the UK, including Edinburgh Castle, and Hillsborough Castle, Northern Ireland. On State Visits, at the State Opening of Parliament, and for The Queen’s Birthday Parade, Green Park near Buckingham Palace is used instead of Hyde Park. This salute is taken by The King’s Troop, Royal Horse Artillery. The first round is fired at noon, or at 11.00 am on The Queen’s official birthday.