The clock tower of the Houses of Parliament is known the world over, but is only part of a sprawling neo-Gothic complex built to house the British legislative system. Parliament has been several hundred years in the making and has changed from a mobile assembly gathered only at the king's behest and for his own ends, through to a static Westminster-based democracy that has alternately challenged, checked and bolstered royal authority. In his introduction to the history of this system and the buildings that have housed it, Richard Tames explains the evolutions of the House of Lords and the House of Commons, how legislation is passed through these chambers and what other functions the houses have performed. He also explores traditions such as the State Opening by the monarch, the role of the Mace, and such officials as the speakers and Black Rod.