I am English (mostly) and have lived in Scotland - but what about Britain?
The energetic reality of Britain, at a gut level, comes almost wholly from the Legends of King Arthur - the matter of Britain; which crops-up all around England, Scotland, Wales and even Brittany.
Like so many people, I have a fascination for Arthur. My main basis for this - its crystallization - was The Once and Future King by TH White, which had a big impact on me in my late teens into early twenties.
But even now I consume quite a lot of Arthurian stuff in the realm of popular art and high art (indeed, I have never read Malory, nor any of the old sources).
An Arthurian setting does not have to be perfect to work its charm on me, even slight hints and pictures are effective enough to keep me interested - so long as I detect a seriousness of intent. I like to visit places with Arthurian associations.
On the other hand I strongly dislike exploitative, crude, vulgar use of the Arthurian legend: the Camelot musical, the idea that JFK's smug coterie was 'like Camelot', Mark Twain's Yankee in King Arthur's Court (or whatever it is called), and - although parts of the movie are very funny (notably the two stupid guards), I did not like the Arthurian links in Monty Python and the Holy Grail.
I like the character of Merlin very much, and also Arthur (as a good, just, somewhat unimaginative but well-meaning Englishman - not, of course, as admirable as the real King Alfred the Great - but better than any other real monarchs!).
I also like the idea of hot-blooded Scots or Welsh knights, and seductive Celtic witches and sorceresses like Nimue and Morgan le Fey.
But I have reservations. I have never liked Lancelot, or Guinevere, and I never liked the Grail plot (a big thing not to like!).
So, King Arthur is the main British legend; indeed (for all its flaws) the only one.
The main English legend is Robin Hood; indeed (for all its flaws) the only one - until Tolkien.
Except that there was the mythic-reality of the Anglo Saxon golden age, upon which (covertly) so much of Englishness was built - St Cuthbert, St Bede, Alfred and so on.
The other dimension - to which I alluded in yesterday's posting of the Border Widow's Lament - is the Border between England and Scotland; which for me has a rather distinct identity, based on the cohesion of Anglo Saxon times and again during the Middle Ages.
Presumably this feeling about the Borders is hereditary - since three grandparents are Northumbrian (two going way-back) and the other came from Ulster, ex-Scots borderers.
Do I believe in such familial influences? Yes, like Tolkien, I do.
I don't try to prove them, nor do I try to explain how such influences work, but they are real.
Ancestral influences can be denied, of course, and existence does not end when they are denied: it merely becomes flat and dead.