"What Celtic heritage are you thinking of Stigweard?"

Good question. Try these for starters:

Well, Wikipedia has an several interesting articles on this subject here, or here to get up and running.

Extant Celtic traditions in England (as well as Scotland) are discussed in the excellent book Twilight of the Celtic Gods, which will can get for considerably less on ebay or by borrowing at your local library.

And that's before I mention King Arthur (a tradition still shared with our Celtic neighbours), The Battersea Shield, Lindow Man, Boudicaa etc etc etc.

My opinion is most of the indiginous population of our Islands are probably decended from the people who arrived after the last ice age. The following periods (Beaker people, Celts, Romans, Saxons, Normans etc) have seen successive cultural shifts rather than actual mass movement of populations we know many British (Celts or whatever) adapted readily to the Roman lifestyle for instance.

This is borne out by DNA studies on very ancient Britons, such as Cheddar Man. His decendant opened the local exhibition about the subject.

I think I prefer the idea of our Islands without borders which is the land our Celtic ancestors would have known before the Roman invasion.

A national anthem for England? I like Spancil Hill.