The Parliament of the United Kingdom of Great Britain and Northern Ireland (commonly referred to as the British Parliament, the Westminster Parliament or, formerly, the Imperial Parliament) is the supreme legislative body in the United Kingdom and British overseas territories, located in London. Parliament alone possesses legislative supremacy and thereby ultimate power over all other political bodies in the UK and its territories. At its head is the Sovereign, Queen Elizabeth II.
The parliament is bicameral, with an upper house, the House of Lords, and a lower house, the House of Commons. The Queen is the third component of the legislature. The House of Lords includes two different types of members: the Lords Spiritual (the senior bishops of the Church of England) and the Lords Temporal (members of the Peerage) whose members are not elected by the population at large, but are appointed by the Sovereign on advice of the Prime Minister. Prior to the opening of the Supreme Court in October 2009 the House of Lords also performed a judicial role through the Law Lords. The House of Commons is a democratically elected chamber with elections to it held at least every 5 years. The two Houses meet in separate chambers in the Palace of Westminster (commonly known as the Houses of Parliament), in London. By constitutional convention, all government ministers, including the Prime Minister, are members of the House of Commons or, less often, the House of Lords, and are thereby accountable to the respective branches of the legislature.
The Parliament of Great Britain was formed in 1707 following the ratification of the Treaty of Union by both the Parliament of England and Parliament of Scotland passing Acts of Union. However, in practice the parliament was a continuation of the English parliament with the addition of Scottish MPs and peers. Parliament was further enlarged by the ratification by the Parliament of Great Britain and the Parliament of Ireland of the Act of Union (1800), which abolished the Irish Parliament; this added 100 Irish members to the Commons and 32 to the Lords to create the Parliament of the United Kingdom of Great Britain and Ireland. It has been called "the mother of parliaments", its democratic institutions having set the standards for many democracies throughout the world, and the United Kingdom parliament is the largest Anglophone legislative body in the world.
In theory, supreme legislative power is vested in the Queen-in-Parliament; in practice in modern times, real power is vested in the House of Commons, as the Sovereign generally acts on the advice of the Prime Minister and the powers of the House of Lords have been limited.
Following the Treaty of Union in 1706, Acts of Union, ratifying the Treaty, were passed in both the Parliament of England and the Parliament of Scotland, which created a new United Kingdom of Great Britain. The Acts dissolved both parliaments, replacing them with a new Parliament of the Kingdom of Great Britain based in the former home of the English parliament. All the traditions, procedures, and standing orders of the English parliament were retained, as were the incumbent officers, and members representing England comprised the overwhelming majority of the new body. It was not even considered necessary to hold a new general election. While Scots law and Scottish legislation remained separate, the legislation was now dealt with by the new parliament.
After the Hanoverian George I ascended the throne in 1714 through an Act of Parliament, power began to shift from the Sovereign, and by the end of his reign the position of the ministers—who had to rely on Parliament for support—was cemented. Towards the end of the 18th century the monarch still had considerable influence over Parliament, which was dominated by the English aristocracy, by means of patronage, but had ceased to exert direct power: for instance, the last occasion Royal Assent was withheld, was in 1708 by Queen Anne. At general elections the vote was restricted to freeholders and landowners, in constituencies that were out of date, so that in many "rotten boroughs" seats could be bought while major cities remained unrepresented. Reformers and Radicals sought parliamentary reform, but as the Napoleonic Wars developed the government became repressive against dissent and progress toward reform was stalled.
The principle of ministerial responsibility to the lower House did not develop until the 19th century—the House of Lords was superior to the House of Commons both in theory and in practice. Members of the House of Commons were elected in an antiquated electoral system, under which constituencies of vastly different sizes existed. Thus, the borough of Old Sarum, with seven voters, could elect two members, as could the borough of Dunwich, which had completely disappeared into the sea due to land erosion. In many cases, members of the Upper House also controlled tiny constituencies, known as pocket or rotten boroughs, and could ensure the election of their relatives or supporters. Many seats in the House of Commons were "owned" by the Lords. After the reforms of the 19th century, beginning with the Reform Act 1832, the electoral system in the lower House was much more regularised. No longer dependent on the upper House for their seats, members of the House of Commons began to grow more assertive.
The supremacy of the British House of Commons was established in the early 20th century. In 1909, the Commons passed the so-called "People's Budget", which made numerous changes to the taxation system in a manner detrimental to wealthy landowners. The House of Lords, which consisted mostly of powerful landowners, rejected the Budget. On the basis of the Budget's popularity and the Lords' consequent unpopularity, the Liberal Party narrowly won two general elections in 1910. Using the result as a mandate, the Liberal Prime Minister, Herbert Henry Asquith, introduced the Parliament bill, which sought to restrict the powers of the House of Lords. (He did not reintroduce the land tax provision of the People's Budget). When the Lords refused to pass the bill, Asquith countered with a promise extracted from the King in secret before the second general election of 1910 and requested the creation of several hundred Liberal peers so as to erase the Conservative majority in the House of Lords. In the face of such a threat, the House of Lords narrowly passed the bill. The Parliament Act 1911, as it became, prevented the Lords from blocking a money bill (a bill dealing with taxation), and allowed them to delay any other bill for a maximum of three sessions (reduced to two sessions in 1949), after which it could become law over their objections. However, regardless of the Parliament Acts of 1911 and 1949, The House of Lords has always retained the unrestricted power to be able to block and veto any bill outright which attempts to extend the life of parliament if the Lords do not believe it to be appropriate, democratic or fitting. In this case, the Parliament Acts can not be used to override the decision of the House of Lords.
The Government of Ireland Act 1920 created the parliaments of Northern Ireland and Southern Ireland and reduced the representation of both parts at Westminster. (The number of Northern Ireland seats was increased again after the introduction of direct rule in 1973.) The Irish Free State became independent in 1922, and in 1927 parliament was renamed the Parliament of the United Kingdom of Great Britain and Northern Ireland.
Further reforms to the House of Lords have been made during the 20th century. The Life Peerages Act 1958 authorised the regular creation of life peerage dignities. By the 1960s, the regular creation of hereditary peerage dignities had ceased; thereafter, almost all new peers were life peers only. More recently, the House of Lords Act 1999 removed the automatic right of hereditary peers to sit in the Upper House (although it made an exception for 92 of them on a temporary basis, to be elected to life-terms by the other hereditary peers with by-elections upon their death). The House of Lords is now a chamber that is subordinate to the House of Commons. Additionally, the Constitutional Reform Act 2005 led to abolition of the judicial functions of the House of Lords with the creation of the new Supreme Court of the United Kingdom in October 2009.