It has evolved into the nation's sovereign power, while the monarchy remains sovereign in name only.

Technically, it consists of the monarch, the House of Commons, and the House of Lords, but the term usually refers only to Commons, a democratically elected body of 651 members.

The House of Lords is composed of peers and Anglican prelates. Since 1911 its powers have been negligible.

The House of Commons is presided over by a nonpartisan speaker elected by Commons, which also elects the PRIME MINISTER; the executive head of government, by modern tradition, must be a member of Commons.

The rest of the government's ministers, the CABINET, may be selected from either house. Thus, the executive branch is, in effect, a committee of the legislature. Elections must be held every five years; the prime minister may call elections earlier, If the party in power fails to obtain a parliamentary majority on an important issue, it may call a general election.

The major parties in Parliament are Conservative, Labor, and the coalition of Social Democrats and Liberals.

The origins of Parliament go back to the medieval Curia Regis, or great council, a body of noble and ecclesiastical advisers to the monarch that evolved into the House of Lords.

Quasi-legislative, it was primarily a judicial and executive body. In the 13th cent. representatives of the knights and burgesses were also assembled to approve royal of the monarchy.

During the ENGLISH CIVIL WAR (1642-48) and its aftermath Parliament gained legislative supremacy over taxation and expenditures.

Parliamentary sovereignty was permanently affirmed by the GLORIOUS REVOLUTION (1688). Demands for representation by the new classes created by the INDUSTRIAL REVOLUTION led in the 19th century to passage of REFORM BILLS which greatly extended suffrage; universal male and female suffrage was granted in the 20th century.

Ben: This 316ft clock-tower was completed between 1858-59.Big Ben is named, probably, after Sir Benjamin Hall, the First Commissioner of Works.

Big Ben was first broadcast on New Year's Eve in 1923. The light above the clock is lit while the Commons is sitting. Big Ben weighs over 13 tons.

The clock mechanism, alone, weights about 5 tons. The figures on the clock face are about 2 feet long, the minute spaces are 1 ft. square; and the copper minute hands are14 ft. Long.

Whitechapel Bell Foundry - Makers of Big Ben and the Liberty Bell. Also hand bells, tower bells, clock bells, carillons, and turret bells.

House Of Commons Chamber