"Wherefore we will and firmly order that the English Church be free, and that the men in our kingdom have and hold all the aforesaid liberties, rights, and concessions, well and peaceably, freely and quietly, fully and wholly, for themselves and their heirs, of us and our heirs, in all respects and in all places forever, as is aforesaid. An oath, moreover, has been taken, as well on our part as on the part of the barons, that all these conditions aforesaid shall be kept in good faith and without evil intent. Given under our hand - the above named and many others being witnesses - in the meadow which is called Runnymede, between Windsor and Staines, on the fifteenth day of June, in the seventeenth year of our reign."
—Final article of Magna Carta
"Since 1832 we have been gradually excluding the voter from government."The United Kingdom of Great Britain and Northern Ireland is a constitutional monarchy, meaning that it is officially "ruled" by a monarch whose powers are controlled by constitutional law. In reality, the monarch is a powerless symbolic figurehead and the country is governed by its legislature: a Parliament made up by the House of Commons and the House of Lords. Although Britain has a parliamentary system and the Prime Minister, the de facto head of government, is supposed to simply be the executive of a ruling political party, some recent Prime Ministers, notably Margaret Thatcher and Tony Blair, have tended towards a "Presidential" executive style of rule. More concisely, the monarch is head of state while the prime minister is the head of government compared to a nation like the US where the head of state and head of government are the same person. An extremely important thing to note about the British government is that it is more or less synonymous with Parliament (the Civil Service notwithstanding): all authority flows from Westminster. Indeed, the "keystone" of the British constitutional order as identified by the celebrated AV Dicey is this: "Parliament...has...the right to make or unmake any law whatever, and further, that no person or body is recognized by the law of England as having a right to override or set aside the legislation of parliament."note This setup is a result of the English Civil War (1641–51), the result of which was the monarchy handing over all its power (which in the Tudor era had been de facto absolute) to Parliament—a process helped by the fact that George I and II barely spoke English and didn't much care for governing Britain anyway—and incidentally resembles Thomas Hobbes' conception of government. In any case, though this sounds rather scary at first—in theory, British liberty could be dead with a single Act of Parliamentnote — the UK's membership in the EU and its institutions, as well as a couple of other well-enforced treaties, have added a measure of restriction to the actions of Parliament; for the first time, Parliament has to deal with potentially making illegal laws.note
—Sir Humphrey Appleby, Yes, Prime Minister
The House of CommonsThe House of Commons is staffed by Members of Parliament (MPs) who are elected by each constituency. These are similar to a Congressional district in the US—a large city will have multiple constituencies. A constituency is represented by a single MP. Each of these constituencies will have an individual name. Every decade or so, the boundaries are re-drawn by the non-partisan Boundary Commission, which does take representations from the parties. The House of Commons is elected for a period of 5 years (elections used to be called at any earlier time at the Prime Minister's whim, but this practice has been recently abolished in favour of fixed-term Parliaments) or can be earlier if the government loses a vote of confidence. MPs are elected on the basis that the candidate winning the most votes is declared the winner, even if they only have one more vote than the next candidate when there are multiple candidates; i.e. it is not necessary to win more than 50% of the votes cast. Results are only given for the whole constituency, not individual wards. When boundaries change, the "results" of the previous election for the new seats are estimated by the media from local council results. These should be treated with some caution. When in the Commons, MPs are not addressed by each other by name, but as "The Honourable Member for [name of constituency]" / "My Honourable friend" for someone from your own party, or "The Honourable gentleman/lady" for people not in your party. There are some varying titles, such as "Right Honourable", used for members of the Privy Council, "Learned" (pronounced "learn-ed") for MPs who are also barristers, and "Right Honourable and Learned" for MPs who are barristers and members of the Privy Council. Parliamentary debates and question times are far more rowdy than the (modern) United States Congress, with creative insults and heckling being the order of the day, but Floor Fights are very rare. The chamber is presided over by the Speaker or one of his/her deputies. The Speaker is a non-partisan figure (once elected Speaker, they drop their party affiliation, and ascend to the Lords after retiring as an MP), and during debates in the Commons, all remarks are addressed to the Speaker; speaking directly to your opposite number and using words like "you" gets you a slapped wrist. Particularly controversial media issues may be raised in Parliament, including this particular gem from a Conservative MP. The current Speaker is John Bercow, a (former) Conservative from Buckingham. The Speaker, in a tie, will nearly always vote to keep debate open and will almost never vote for a bill, as doing so would create a majority where one did not exist; the main exception is if the bill is a confidence or supply measure—i.e., if the bill fails, the government collapses and either a new PM and new government must be chosen or new elections must be held—in which case the Speaker will generally vote in favor.
Elections to the CommonsThere are 650 elected MPs, all but two of whom note are also members of a political party. Westminster is most near to a "two-and-a-half party" system, with the dominant parties being Labour and the Conservatives, and the perpetual third party the Liberal Democrats. The first-past-the-post electoral system slightly favours Labour and heavily disadvantages the Liberal Democrats (and small parties in general), reflecting Labour's traditional large support in the cities and the Lib Dems' having a fairly even support nationwide; in theory, the Lib Dems could even beat the Conservatives into second and Labour could remain the largest party with twice as many as the Lib Dems. The voting system can, and has done, in some cases cause political parties to lose seats even though their popular vote increases; this happens to the minor parties more than Labour and the Conservatives, although Labour actually managed to lose an election that way: in 1951 Clement Attlee beat Winston Churchill by three-quarters of a million votes, but ended up with fewer seats. Proposals have been made to switch to a more proportional system, with ultimately little success — the main argument against the change was that it would ensure weak, minority governments or coalitions. On 5 May 2011, the UK held a referendum on whether to switch from the existing First Past The Post system to Alternative Vote, which if passed was expected to more fairly represent smaller parties like the Lib Dems and the Greens. There were vocal campaigns both for and against the switch to AV. Because of a legendarily terrible campaign from the Yes side that will be autopsied for years to come, it was defeated resoundingly, leading to the coalition becoming a lot more adversarial (Summary, in musical form). The most recent general election took place on 6 May 2010, with the key issues being immigration, the economy, and, late into the campaign, electoral reform; it produced a "hung parliament" with the Conservatives being the largest party, bringing the aspect of electoral reform to the centre of political discourse. It is worth noting that because a General Election is fought over 650 small constituencies, which change little (if at all) between elections, small Political Parties can make gains by concentrating all their efforts on one constituency. This is how the Green Party won their only seat in Brighton Pavillion, and why UKIP haven't won any despite having more support nationwide. Any Parliamentary constituency has a tendency to become a two horse race with a bunch of also-rans, but exactly which of the parties are the two front runners depends on the constituency. Scottish seats tend to be SNP-Labour (in urban areas) or SNP-Lib Dem (in rural and island areas), the South of England tends to be Lib Dem-Tory battles outside of urban Labour areas, and some of the deepest rural areas are shaping up as UKIP-Tory battlegrounds.
After the electionsThe party that can command a majority is the ruling party. Their elected leader, chosen by the party through varying methods,note then chooses a cabinet of which he/she serves as primus inter pares (first among equals). These men and women are responsible for various departments of government; there are currently 27 cabinet members who hold 42 positions—during the Labour governments of Blair and Brown, Harriet Harman acquired the nickname "Three Hats Harman" for having three separate posts—including the Prime Minister. They're often referred to as "The X Secretary", but their actual title is "The Secretary of State for X". Cabinet membership is not subject to Parliamentary approval, and may not even be along party lines (although, these days, they nearly always are), so chops and changes frequently, with much attendant press speculation. Contrary to public assumptions, and the press' frequent bellyaching, the Prime Minister is not directly elected, thus calling a PM "unelected" doesn't really mean anything, except to take a swipe at a PM you don't like; Gordon Brown got a lot of this to the point of being the press' Butt Monkey in the run-up to the 2010 election, despite the fact that, of the 23 Prime Ministers since 1900, fourteen ascended to the position in the middle of a Government; even Winston Churchill was "unelected" for his first run at the premiership during World War II (in fact, Churchill never actually "won" a democratic election - his second government in 1951 was, as detailed above, a fluke of the system as he took considerably fewer votes than his Labour opponent). Below this people are the Ministers of State and the Parliamentary Under-Secretaries of State (PUSSYs). Below them are the Parliamentary Private Secretaries (PPS), who are unpaid lackeys for the Cabinet members. They sit behind the front bench at Prime Minister's Questions, with the result that the camera cuts their heads off. Those who are not chosen or refuse offers for the Cabinet or for junior ministerial office are called "backbenchers", as opposed to those who sit on the Government "front bench". The official title of the largest party that is not in Government is "Hernote Majesty's Loyal Opposition", and their job description is to question and hold to account "Her Majesty's Government" to ensure that any policies have been well thought-out. The leader of the largest party out of government is also known as "The Leader of the Opposition" and is a member of the Privy Council. The Opposition party will also select a cabinet, known as a Shadow Cabinet. Despite sounding very cool, this cabinet does not do anything in practical terms. Instead, their job is to call on their cabinet counterpart during meetings in the Commons, typically to question their decisions (the other MPs, including the backbenchers, can also do this to whomever they wish). They also work out the party's policies in relation to their position—i.e., the Shadow Secretary for Education will look at schools and universities—ready for the next election. The Lib Dems, while in opposition, also select their own "frontbench team" too, from the few MPs they have (as it is, they are currently in coalition with the Tories and have five of a total of 23 official Cabinet seats). Unlike in the United States, changes of government occur very quickly. It is possible, and common, for the polls to close at 10 pm on Thursday, the result be more-or-less certain at about 3am on Friday, the defeated Prime Minister to go to Buckingham Palace to resign before lunch on Friday, with the new PM appointed before Friday evening and appointments sorted out over the weekend. Obviously, there are times when the result goes right down to the wire and the result not known until breakfast the following morning, most lately in 1992 (Conservative majority of 20) and 2010. The following list includes political parties with regional representation or better,note ordered by numbers of MPs, MEPs (Members of the European Parliament, out of 73), MSPs (Members of the Scottish Parliament, out of 129), MLAs (Members of the Northern Ireland Assembly, out of 108), and AMs (Members of the National Assembly of Wales, out of 60), where applicable.
The Big Three parties
The regional parties
In Great Britain
In Northern Ireland
The minor national parties
Not really parties, but listed for completion:
And last, but certainly not least...
The parties and electionsUKIP and the Green Party have had very little electoral success, despite levels of support that would suggest returning a handful of legislators (2010: 3.0% and 1.0% respectively); the first MP from either party to get elected to the Commonsnote was the Green Party leader Caroline Lucas in 2010; however, they have been more successful in getting members elected to the European Parliament, although the UKIP, in common with a number of other minor parties in history, have had a party member defect to them. Until 2009, the BNP (2010: 1.9%) have never been elected to anything more significant than a few local council seats; they now have two MEPs. Before anyone gets too worried about the implications, they actually received fewer votes than the previous election, but lower turnout, in part due to an ongoing political scandal affecting the main parties more than hard-line BNP supporters, meant they received a higher proportion of the total. Given that it effectively disenfranchises a great deal of the population, this along with the Liberal Democrats' low seats-to-votes ratio, is one of the most common arguments for proportional representation. Political parties based in Great Britain, especially Labour, the Conservatives, and the Liberal Democrats, do not generally contest elections in Northern Ireland, although the Conservative party has contested elections and failed to make much of an impact. Instead, there is a completely separate set of political parties: Sinn Féin and the Social Democratic and Labour Party (SDLP) are mainly Catholic parties; the Democratic Unionist Party (DUP) and Ulster Unionist Party (UUP) are mainly Protestant parties; and the Alliance Party is non-sectarian. Sinn Féin is an abstentionist party, i.e. when its candidates win an election to the House of Commons, they refuse to take their seats as they would have to swear an oath of allegiance to the Crown. Sinn Féin also fields candidates across the border in the Republic of Ireland (where they do take their seats, but have historically done far worse; the 2011 elections did see a large improvement, however, and their candidate finished third, out of seven candidates, in the 2011 Presidential election). It is currently the only political party to actively operate in both the UK and Ireland.note
Major Defunct Parties:
TOW has a list of all political parties of note here.
The House of LordsPartially made up of the remnants of Britain's upper classes; a combination of hereditary lords (whose peerages are passed from parents to children), bishops known as Lords Spiritual, and other nobles, leaving it traditionally conservative-with-a-very-small-c. Tony Blair's Labour government was central in stripping some of the power from the House of Lords (in an attempt to stifle opposition to Blair), including removing all but 92 of the hereditary peers and replacing them with a wide range of peers from all walks of life, particularly those with scientific or other specialist knowledge, although there was a controversy about some candidates who got into office after making large donations to the Labour Party, in the Cash for Honours controversy. These were elected by committees as part of a Government drive. There were votes in 2007 to remove the last peers from the House, which were blocked by the Lords. The purpose of The House of Lords is to act as a checking system for The House of Commons and to scrutinize any bills that are passed through Parliament (although they can also submit new bills, this happens only rarely). This rather divides opinion in political experts; some think that unelected members of Parliament goes against the principles of democracy and that the second House should also be elected by the public, while others believe that having two elected chambers would be a bad idea, since it would lead to the same party being dominant in both, and thus be able to force bills through with no opposition. The Lords consist of 741 active members and have the power to veto or delay any move by the Commons, which explains why they still exist. However, there are restrictions; the Lords cannot permanently affect any bill that seeks to fulfill promises made in the Government's manifesto, nor can they affect any bill that is concerned solely with public money or taxation. The Government can also force a bill past the House of Lords via the Parliament Acts 1911 and 1949, although this is rare, being last done over foxhunting. If you were wondering how a bill allowing the Commons to bypass the Lords was created, the Lords voted in favour of it (eventually; the Prime Minister got the King to threaten to stack the House in his favour by appointing more Lords). The House of Lords historically featured Law Lords (formally the Lords of Appeal in Ordinary), who acted as the highest court of appeal in the UK (usually as the Appellate Committee of the House of Lords, with decisions being presented and pro forma passed as motions by the Lords as a whole). However, the Blair Government, desiring to increase the separation of the judiciary and the legislature (partly because the EU had made some noises about the arrangement being suspicious), abolished the system. The new Supreme Court of the United Kingdom was established in 2009, taking over the Appellate Committee's duties...and pretty much everything else about the Appellate Committee, as well, since the Law Lords all became Supreme Court Justices, the Law Lords who had become Justices got to keep their seats in the House (not that it mattered, since they never used them), and future Justices would be given baronial titles without seats. So essentially, nothing changed.
The Privy CouncilThe Privy Council has nothing, usually, to do with toilets. It has a lot less power than it used to (the Cabinet, a subcommittee, has most of that). It consists of former and current Cabinet members, leaders of the big three political parties, plus a few other people that get invited to the show. The main advantages of membership is that a) it's for life, b) you can call yourself "Right Honourable", c) you can sit on the steps of the throne during debates if you're a member of the House of Lords and d) you get access to top secret documents. The Privy Council also has a Judicial Committee, consisting of the Justices of the Supreme Court and a few other judges. Its domestic jurisdiction, once wide-ranging, is now limited to a few random tribunals which for the most part almost nobody has heard of or cares about (the ecclesiastical courts? the High Court of Chivalry? The Disciplinary Committee of the Royal College of Veterinary Surgeons?note ); the main exception is that it hears cases on appeal in admiralty—that is, the law of seagoing vessels—from certain courts. It may also give "advice" should the Government ask for it. However, it serves as the highest court of appeal for Britain's Crown Dependencies (The Channel Islands and the Isle of Man) and Overseas Territories (numerous, most notably Gibraltar and The Falkland Islands), certain Commonwealth Realms, certain Commonwealth Republics, and the Sultanate of Brunei. When sitting for this purpose, jurists from the country in question are appointed to the Privy Council to hear the case. This procedure has been abolished in the more developed Commonwealth Realms, although it existed more recently than you might think—Australia abolished it so recently that one of the most famous Judicial Committee decisions, the "Wagon Mound" case of 1961, was actually an appeal from the Supreme Court of New South Wales. Upon the death of the monarch, sovereign power devolves to the Privy Council until the latter officially proclaims the heir to be King or Queen.
Government Departments, Agencies and The Civil ServiceTo actually administer the country, there are a considerable number of government bodies. The highest rank are the Government Departments—the name "Ministry" is virtually unused now—, many of whom are based in Whitehall — although, in true British fashion, stuff will be farmed out elsewhere). These departments have a tendency to chop and change with each new administration, since there is no law regulating them. However, the ones that have stood the test of time are:
Devolution of PowerAlthough the UK Parliament is in the Westminster area of London, England, the country of Scotland has its own Parliament, and Wales and Northern Ireland have national/regional assemblies, while London has the Greater London Authority. These structures have limited powers over their respective countries; most matters remain in the hands of the UK national Government. They each have different degrees of self-control, with Scotland having devolved the most power (and having its own, entirely different legal system). Each of the three devolved administations also contains a distinguishable nationalist element. The Scottish Parliament has the SNP, the Welsh Assembly has Plaid Cymru, and the Northern Ireland Assembly has Sinn Féin and the SDLP. These parties all advocate a separation of their respective country from the United Kingdom in some form or another. With the exception of the Scottish Parliament, however, these elements have not usually been in the majority in devolved elections. England does not currently have its own parliament - possibly because England's size relative to other parts of the UK is such that an English parliament will not be more representative than the UK parliament. There have been proposals for English regions to have devolved parliaments or 'regional assemblies', and there is currently a Greater London Assembly, that has similar powers to a devolved parliament, but no others as yet. Northern Ireland previously had a devolved parliament (Stormont) with an actual Prime Minister (between 1921-1972). This wielded a great deal more power than the current Assembly but was abolished in 1972 due to the worsening Troubles, with the country being directly ruled from Westminster. The current Northern Ireland Assembly only took over officially in 2002. The Scottish Parliament, Welsh National Assembly, Northern Ireland Assembly, and the Greater London Assembly are elected for fixed terms of four years and have an element of proportional representation in the electoral process to ensure that the eventual composition of the elected assembly more nearly reflects the proportion of votes cast for the various parties e.g. the Welsh Assembly has 60 members, 40 of whom are elected for geographical constituencies which match the 40 House of Commons seats which Wales has; the other 20 members are elected from regional lists to adjust the overall seat distribution in each region in line with the proportion of votes cast between the parties. Following the 2011 elections, control of the devolved parliaments is as follows:
Local GovernmentLocal government in the UK is a very complex subject, with not all areas having the same system. Most areas of England have County Councils, with District Councils below them (many districts are called Boroughs or Cities). However, there are some Unitary Authorities (whose councils are either called London Boroughs, Metropolitan Boroughs, Cities, Counties, Districts or simply just Councils) which can be best thought of by Americans as what you would get if the entire of Southern California became one state and combined its local and state authorities into one government. The whole of Scotland, Wales and Northern Ireland are divided into Unitary Authorities. In Northern Ireland there are known as Districts though 2 have City Status, Scotland has council areas (4 being City Councils) and Wales has Principal Areas known as either Counties, Cities or County Boroughs. In most rural parts and some urban areas of England the districts are sub-divided into Civil Parishes which are run by Parish Councils despite which, despite what it looks like in the BritCom The Vicar of Dibley, have nothing to do with the Church Of England (which is also divided into parishes which are run by Parochial Church Councils). Sometimes the 2 councils may have the same people on them but they are totally seperate identies. Parish Councils have very little power normally but if they cover a small town the local district or county council may devolve certain matters to them - eg public parks. Parish Councils that cover towns are called Town Councils and some are even City Councils these councils are led by a Town or City Mayors. Some parishes have too small a population to have a council and instead have an annual parish meeting where the whole parish is invited to discuss local matters. Wales has similar bodies called Community Councils. The equivalent bodies no longer exist in Scotland or Northern Ireland. Local government is responsible for things like planning, schools, libraries and refuse collection. Local councils are elected every May: which ones and which seats vary from year to year, but most seats are generally four years long. These elections, like US mid-terms, are often an opportunity to protest against the government. Local issues also play a big role. All borough and city councils have a Mayor or a in Scotland a Provost. Some are known as Lord Mayors or Provosts. This is usually elected by the Councillors from among themselves, and involves mainly doing ceremonial and charity work. However, some areas have an elected Mayor, most notably Hartlepool, which in 2002 elected the guy who was in the suit of their town's football mascot, H'Angus The Monkeynote . Despite the fact that he didn't actually expect to get elected, he's done a great job and in 2009 became the first mayor in England to be re-elected for a third term. Some more stuff on specific cities and towns is covered in Other British Towns And Cities. N.B.: The UK local government divisions are not the same as the postal ones, which are based on older county lines.
The Royal FamilyOriginally formed as warring Anglo-Saxons joined together under one leader, for hundreds of years the monarch served as the de facto leader of England, passing on the power to a relative, preferably a son, upon death. After the childless "Virgin Queen" Elizabeth died, the Scottish monarch James VI of the House of Stuart, her first cousin twice removed (being the grandson of her cousin James V), came to the throne as James I of England and Ireland and VI of Scotland. Unfortunately his son, Charles I, wasn't too good at the job he later inherited, as his opposition to Parliament triggered the English Civil War, which ended with Charles getting beheaded in 1649. Following the King's execution, Parliament declared the abolition of the monarchy and the formation of a republic called the "Commonwealth" governed by Parliament in its own right: an extremely radical concept for those times. Despite officially ruling in the name of the people, the Commonwealth was dominated by both army, who had fought the King's men during the civil war and were essentially the reason it existed, and followers of the Puritan faith whose influence meant that the Commonwealth was often rather more like a theocratic "Christian republic" than a republic in the Roman, American or French understanding. The Puritans, as their name suggests, weren't fond of fun and many strict religious rules were enforced including the infamous banning of Christmas festivities. This set-up lasted only a few years until an MP and military commander in the civil war called Oliver Cromwell (who had also conquered Scotland and Ireland and absorbed them into the Commonwealth, the latter during a campaign that is infamous in Ireland for its brutality) forcibly dissolved the sitting Parliament, and therefore the government, with the help of the army and arranged for his installation as "Lord Protector" in 1653 (a proto-President-for-life). This was along with an appointed Parliament composed of people Cromwell regarded as worthy men, though were later an actually elected Parliament, but still subject to restrictions to keep out royalists. To pay for the military campaigns, Cromwell forcibly ejected Catholic landowners in Ireland in favour of Puritan settlers. Cromwell was a Puritan and his objection to the sitting Parliament had been that they were unworthy and ungodly men, and were attempting to sustain themselves indefinitely. The new regime proved stable enough, although on his death in 1658 power passed to his son, Richard, who was unable to control Parliament and the army and resigned his office after only nine months in power restoring the "genuine" Parliamentary republic. Another year of political turmoil demonstrated that someone was needed to restore the power vacuum that Cromwell's death had created and a new Parliament was elected which voted in the summer of 1660 to invite Charles' son back to take the throne thus restoring the monarchy as well as the independence of Scotland. Charles II, unlike his father, managed to hold the country together although a major disagreement with Parliament over his intention that his Catholic brother James should succeed him lead to him dissolving Parliament and, very much in the family tradition, ruling as an absolute monarch for his remaining years. When James II came to the throne intrigues began against him immediately and, after only three years, he was deposed in a coup d'etat known as the "Glorious Revolution" in 1688 in which the Stadtholder of the Dutch Republic, William III of Orange, was invited to invade England and become King William III (ruling jointly with his wife Mary, James II's estranged daughter and who provided the "legal" window-dressing for William's claim and who became Mary II). The revolt was successful, James was deposed and Parliament entered a further agreement with the new King severely limiting his powers and ensuring that another Stuart-style "tyrant" could never rule England again. It also contained a clause preventing a Catholic monarch from taking the throne, a clause which still persists. However, many monarchists believed that Parliament had no right to "choose" England's monarch in this manner and became "Jacobites", recognising the ousted line of James II as the legal monarchs of England and Scotland. This movement made two serious attempts at regaining the English throne for the Stuarts, the last in the 1740snote . The 1688 "revolution" and the powerful Parliament and controlled monarchy it created is generally regarded as the basis of the modern British state. At about this time, the Whigs and Tories - predecessors of the Liberal and Conservative Parties, respectively - formed. By 1714, the Protestant branch of the House of Stuart was dead, and the German-speaking George, Elector of Hanover, became King George of Great Britain. On account of King George's near-complete ignorance of the English language and consequent relative lack of interest in his British domains, the institution of Prime Minister (but not officially called such until the 20th Century) cropped up to administer Britain and its already considerable empire. By the time that George I's great-grandson George III (an Englishman through and through, but prone to insanity due to a recurring illness) inherited the throne, Parliament had definitely established its supremacy and the Prime Minister, and not the monarch, was the most important person in the state. The modern monarch doesn't really do all that much: his or her powers are purely ceremonial, a result of Parliament taking on more and more of the monarch's remaining powers in the 18th and 19th century, helped by a succession of monarchs who were, in order, unable to speak English (George I and II), mentally ill (George III), a total dilletante (George IV), very old and only king for seven years (William IV), a woman (Victoria) and another dilletante (Edward VII). There were only three periods when monarchs tried to assert themselves in any serious fashion, and they were ended, respectively, by losing a war in America, the death of George IV and the death of Albert. To be honest, the monarchs would barely have been able to prevent the eroding of their remaining power if they'd made the effort. While the monarch does technically have the ability to veto any act of Parliament, to refuse a nominated Prime Minister, to sack the Prime Minister if he messes up, or to mobilise the army, to actually do so would likely cause a massive public outcry as it would be going against the will of the people by virtue of going against their democratically-elected leader. It is also extremely unlikely that the monarch could face-off against the rest of the British political establishment and win (the last monarch to do anything against the will of Parliament was King William IV in the 19th century and even then his action — appointing his own choice of Prime Minister — was extremely controversial and done at the behest of a coterie of powerful politicians). However, the current Queen is not entirely powerless. As the armed forces swear allegiance to the monarch and not to the Government, should the Prime Minister declare himself a dictatorial leader the queen can directly order them to stand down and, if necessary, turn against Westminster. This would be an awesome ending to a film, if anyone wants to make it. She also holds similar powers over some of the other nations in the Commonwealth via her Governors-General, her official representatives to the Commonwealth realms who swear allegiance to her as their head of state. The entire Australian Parliament was even dismissed by one Governor-General as recently as 1975, mainly because the politicians were arguing too much over money and how it should be spent. Mostly, however, the monarch drinks tea and acts as a source of advice to the Prime Minister. Several prime ministers have attested that this is typically not just ceremony: the Queen has access to most significant government documents, and apparently, has spent several hours a day every day for the last fifty or so years going through them. There's very little she doesn't know about government policy, and her advice has proven invaluable to several Prime Ministers (Tony Blair in particular noted this, much to the annoyance of his republican wife; this is portrayed quite clearly in The Queen). The current monarch, Queen Elizabeth II, is reportedly a fan of the new series of Doctor Who and plays the Wii. Contrary to popular belief, Barack Obama's gift of an iPod to the Queen was not an ill-informed faux pas; while it is true she already had one, she had previously mentioned that it was out of date and would really appreciate a more up to date one. The traditional way to refer to the monarch is "His/Her/Your Majesty" the first time you mention them, and then "sir" or ma'am" thereafter. In the past when more countries had monarchs, the British monarch was sometimes specifically identified as "His/Her Britannic Majesty", which still typically appears on customs documents such as passports. Good etiquette upon meeting the monarch is for a lady to do a small curtsy, or a man to do a small bow, from the head. On presentation to The Queen, the correct formal address is 'Your Majesty' and subsequently 'Ma'am'. However, the official line from the Palace is that there there are no obligatory codes of behaviour - just courtesy. The Queen herself will notice if you slip up, but naturally will not be bothered by it. Such was the power and scope of the British Empire that the Westminster system is still used in many Commonwealth countries, notably Australia, Canada, New Zealand, half the Caribbean, as well a number of countries that still use the system despite no longer recognising the Queen as their Head of State. See The House of Windsor for more about "Queenie" and her family in fact and fiction.
See Irish Political System for the way it works a little west.