Who's asking: Jennifer Lechner, Freeport, ME
The song says, "There'll Always Be an England," and there pretty much always has been an England -- since the eighth century, at least, when Egbert of Wessex first unified Essex, Kent, Surrey and Sussex.
Since then England has been the Pac-Man of nations, gobbling up everything around it (Americans got the idea from somewhere). England and Wales were formally united in 1536; England became "Great Britain" with the annexation of Scotland, in 1707; and "the United Kingdom" formed in 1801, with the addition of Ireland.
The country's official name at that time was "The United Kingdom of Great Britain and Ireland." Since 1927, it's been "The United Kingdom of Great Britain and Northern Ireland."
The "Home Counties," a phrase that comes up frequently in historical British mysteries, are the counties closest to London: Hertfordshire, Essex, Kent, Surrey, Buckinghamshire, and (formerly) Berkshire and Middlesex. The designation comes from the old circuit Court of Assize, in which judges from London would travel around the Home Counties to hear cases during periodically-scheduled sessions. Now the phrase refers to the area considered commuting distance from London.