Gun salutes also occur when Parliament is prorogued by the Queen, on royal births and when a visiting head of state meets the Queen in London, Windsor or Edinburgh. A Royal Salute of 21 Guns is fired at Edinburgh Castle in honour of The Queen or her Personal Representative, the Lord High Commissioner to the General Assembly of the Church of Scotland, when processing in state to the Opening of the General Assembly of the Church of Scotland which occurs annually in May. The significance of the 21 Gun Salute is that the Lord High Commissioner is representing the Sovereign as Head of State.