- Some folks get hot under the collar when their particular part of the British Isles is mischaracterised. Scotland is not part of England, Wales is not part of England. Some object to the Republic of Ireland being identified as part of the British Isles.
This diagram reproduced from http://rationalwiki.org/wiki/United_Kingdom may help to sort things out - or may just further enrage the pedant.
Also on the RationalWiki UK page: The briefest possible history of the UK, The British Empire
Politics, Future, Religion, Money, Trivia, How to refer to its people.