The State Opening of Parliament is the most colourful event of the Parliamentary year, according to the Royal website. It is also the most important, because it brings together the three elements of the British legislature (the House of Commons, the House of Lords and The Queen).
The ceremony therefore represents the Crown in Parliament.
Her Majesty has opened Parliament on 58 occasions and has only missed two during her reign. The website says the first time was in 1959 when she was pregnant with Prince Andrew and the second in 1963 when she was expecting Prince Edward.
The ceremony traditionally takes place in the northern Autumn, unless a General Election has taken place. This was the case in 2010.
Before The Queen travels to Parliament from Buckingham Palace, Yeomen of the Guard search the cellars of the Houses of Parliament.
This dates back to the Gunpowder Plot of 1605, when Guy Fawkes was arrested whilst preparing to blow up Parliament.
Another tradition is the 'hostage' MP, a Government whip who is held at Buckingham Palace to guarantee the safe return of the monarch.
The Queen goes from Buckingham Palace in a State coach to the Palace of Westminster, usually with The Duke of Edinburgh. The Imperial State Crown is taken in another carriage.
When she arrives The Queen puts on the Imperial State Crown and her parliamentary robe and proceeds to the House of Lords.
Members of the House of Commons are summoned by Black Rod. The door of the House of Commons is slammed in Black Rod's face, but then reopened as a reminder of the right of the Commons to exclude everyone except the Sovereign's messengers.
No monarch has set foot in the House of Commons since Charles I entered the Commons and tried to arrest five Members of Parliament in 1642.
The Queen reads the Speech rom the Throne which has been prepared by the government. Accordingly it sets out the government's programmes for the session.
A modified version of this ceremony is followed in the State Openings of the Australian Parliaments.