The System of Government in Great Britain

Great Britain is a constitutional monarchy with the Queen as the head of state. Britain is divided into four parts: England (London capital), Wales (Cardiff), Scotland (Edinburgh) and Northern Ireland (Belfast).

Constitutional monarchy
A constitutional monarchy is a form of government in which a monarch acts as head of state within the parameters of a written, unwritten or blended constitution. It differs from absolute monarchy in that an absolute monarch serves as the sole source of political power in the state and is not legally bound by any constitution.
Most constitutional monarchies employ a parliamentary system in which the Monarch may have strictly Ceremonial duties or may have Reserve Powers, depending on the constitution, have a directly or indirectly elected prime minister who is the head of government and exercises effective political power.

The head of state is Queen but she can act only on the advice of her ministers. Queen Elizabeth II. lives in Buckingham Palace in London. She has four children – Charles (Prince of Wales) , Anne (Princess Royal) , Andrew (Duke of York) and Edward (Earl of Wessex).

Queen Elizabeth II
Elizabeth II (Elizabeth Alexandra Mary, born 21 April 1926) is the reigning queen and head of state of 16 independent sovereign states known as the Commonwealth realms: the United Kingdom, Canada, Australia, New Zealand, Jamaica, Barbados, the Bahamas, Grenada, Papua New Guinea, the Solomon Islands, Tuvalu, Saint Lucia, Saint Vincent and the Grenadines, Belize, Antigua and Barbuda, and Saint Kitts and Nevis. In addition, as Head of the Commonwealth, she is the figurehead of the 54-member Commonwealth of Nations and, as the British monarch, she is the Supreme Governor of the Church of England.
In 1949, George VI, her father, became the first Head of the Commonwealth, a symbol of the free association of the independent countries comprising the Commonwealth of Nations. On his death in 1952, Elizabeth became Head of the Commonwealth, and constitutional monarch of seven independent Commonwealth countries: the United Kingdom, Canada, Australia, New Zealand, South Africa, Pakistan, and Ceylon. Her coronation in 1953 was the first to be televised. During her reign, which at 58 years is one of the longest for a British monarch, she became queen of 25 other countries within the Commonwealth as they gained independence. Between 1956 and 1992, half of her realms, including South Africa, Pakistan, and Ceylon (renamed Sri Lanka), became republics.

According to the constitution of the United Kingdom, the monarch has the following powers:
The power to appoint and dismiss the Prime Minister
The power to appoint and dismiss other ministers.
The power to summon, prorogue and dissolve Parliament
The power to make war and peace
The power to command the armed forces of the United Kingdom
The power to issue passports
The power to appoint bishops and archbishops of the Church of England
The power to create peers (both life peers and hereditary peers).

The Government is formed by the party which has the majority in Parliament and the Queen appoints its leader as the Prime Minister.
The Prime Minister of the United Kingdom of Great Britain and Northern Ireland is the Head of Her Majesty's Government in the United Kingdom. The Prime Minister and Cabinet (consisting of all the most senior ministers, who are government department heads) are collectively accountable for their policies and actions to the Sovereign, to Parliament, to their political party and ultimately to the electorate. The current Prime Minister, David Cameron, was appointed on 11 May 2010.

The Prime Minister
As the "Head of Her Majesty's Government", the modern Prime Minister is the highest political authority in the United Kingdom: he leads a major political party, generally commands a majority in the House of Commons (the lower house of the Legislature), and is the leader of the Cabinet (the Executive). As such, the incumbent wields both legislative and executive powers. In the House of Commons, the Prime Minister guides the law-making process with the goal of enacting the legislative agenda of the political party he leads. In his executive capacity, the Prime Minister appoints (and may dismiss) all other cabinet members and ministers, and co-ordinates the policies and activities of all government departments, and the staff of the Civil Service. He or She acts as the public "face" and "voice" of Her Majesty's Government, both at home and abroad. Solely upon the advice of the Prime Minister, the Sovereign exercises many of her statutory and prerogative powers: they include the dissolution of Parliament; high judicial, political, official and Church of England ecclesiastical appointments; and the conferral of peerages, knighthoods, decorations and other honours.

The Parliament
The Constitution of the United Kingdom is unwritten, it is based on custom, tradition and common law. The supreme law-making body in the country is Parliament. Parliament consists of: the House of Commons and the House of Lords. The Houses of Parliament are the centre of British government. They were built in last century. British parliamentary system is one of the oldest in the world, it developed slowly during 13th century after King John’s signature of Magna Carta in 1215.

The House of Commons
The House of Commons is the lower house of the Parliament of the United Kingdom, which also comprises the Sovereign and the House of Lords (the upper house). Both Commons and Lords meet in the Palace of Westminster. The Commons is a democratically elected body, consisting of 650 members (since 2010 General Election), who are known as Members of Parliament (MPs). Members are elected through the first-past-the-post system by electoral districts known as constituencies. They hold their seats until Parliament is dissolved (a maximum of five years after the preceding election).
A House of Commons of England evolved at some point in England during the 14th century and, in practice, has been in continuous existence since, becoming the House of Commons of Great Britain after the political union with Scotland, and also, during the nineteenth century, of the United Kingdom of Great Britain and Ireland after the political union with Ireland, finally reaching its current title after independence was given to the Republic of Ireland. The House of Commons was originally far less powerful than the House of Lords, but today its legislative powers greatly exceed those of the Lords.