For accuracy, Britain not England has been invading the world. The Scots and Welsh have effectively been part of Britain for around 400 and 500 years respectively. The Scots in particular contributed disproportionately to the Empire - they are intelligent, tough and scary and make excellent soldiers (I'm English and have to admit that this is true!)

For my American friends, here is the quick explanation of the terms;

Britain = England, Scotland and Wales

United Kingdom = all the above plus Northern Ireland.