Greater London is an area which contains London, the capital of the United Kingdom (which itself centres on the Cities of London and Westminster) and a number of surrounding boroughs which are administered as London boroughs and which are the overall executive responsibility of the Mayor of London. It contains a large number of constituencies, each represented by an MP and it should be noted that these are not the same as nor even always continguous with the borders of the boroughs.

Many parts of Greater London were originally administered by the counties which surround London and these counties are often called the home counties. Enfield, for example, used to be classed as being part of Middlesex, but is now near the northern border of Greater London. Greater London's borders often coincide with a zone of 'green belt': areas where it has been decided that open spaces, parks, forests and wildlife reserves should act as a buffer against urban sprawl. London has numerous landmarks, anything from Big Ben and the Houses of Parliament to Karl Marx's grave in Highgate Cemetery.

Greater London contains more than 9 million inhabitants, a number growing daily, and as this is approximately 1/7 of the population of the UK, it can be seen that Greater Londoners have a large influence on the rest of the country politically and this is enhanced by the concentration of skilled workers gravitating towards the capital.