The exact location, time and method of the entry of chess, or rather its immediate precursor Shatranj, into western Europe is unknown, however linguistic evidence suggest that it was almost certainly transmitted via the Arab world.
Philological evidence points to an earlier date than archeological and literary evidence currently suggests, indicating that the game entered Europe perhaps as early as 900 AD.
In the beginning chess was only played by peers at the court. The only exception is the so-called chess village Ströbeck, where chess became popular among the farmers in the early 11th century already.
England, Scotland, Ireland, Wales, Jersey and Guernsey all have separate national chess federations, and send their own teams to international chess competitions. The English Chess Federation, which in 2005 replaced the long established British Chess Federation, is responsible for the organisation of chess in England, and also organises the annual British Chess Championship on behalf of all the UK federations. Tournament organisers and chess clubs send game results and appropriate fees to the ECF which then compiles ratings that measure the playing strength of active players.
The basis of English (ECF) ratings broadly speaking is that the difference in ratings is half the difference in percentage scores. That is, if player A beats player B in a match 8 to 2 (60% difference), you would expect his grade to be about 30 points higher. Grades are calculated by averaging out points gained or lost against opponents whose grades are known already. There are two sets of grades, one for rapidplay games (30 minutes each per game), the other for standard games (two minutes or more average per move).
In addition to games within the club, there are leagues in which clubs compete with each other and these games will also be graded. Aside from the many local leagues, the Four Nations Chess League (4NCL) is effectively a prestigious tournament run on a league format, to which many of the British and world's elite players are attracted.
The most famous tournament held in Britain is probably the Hastings International Chess Congress, which runs from late December to early January.
Tournaments usually pay prizes both for the first three or four places and for people who get the most points within a particular range of grades, but the vast majority of players who enter them play for recreation.