I’m originally from England. I don’t say Britain not because I have a problem with it but because it’s more of a political construct than England. Yes, there are probably many arguments against these definitions. For one the North is very different to the South and especially the Southeast. For decades Britain’s Labor Party relied on its ‘Red Wall’, a collection of safe seats in the industrial heartland of England, which incredibly voted for the Tories, giving our Prime Minister or Boris, a massive majority in Parliament.
Parts of England, like Cornwall have never acceded to English rule and going into the county next door, Devon, is often referred to as ‘going to England’. Cornwall was a Celtic province, with its own language which has now died out. The Isle of Man in the Irish Sea was another distinctive Celtic land with its own Parliament, The Tynwald, probably the oldest consecutive parliament on Earth. Manx was the Gaelic language used on Man but again it has largely died out. The six counties of Ulster are part of Great Britain, and distinct from Eire or the Irish Republic. Irish Gaelic is still spoken in Ulster but is not very common. The Protestant majority of Ulster have a distinctive accent and language called Lallans, which is derived from Scotland. The great Scots Poet Robbie Burns wrote in a mix of English and Lallans.
The Celtic margins which border England are Wales and Scotland. Welsh is commonly spoken, especially in North Wales. Scottish Gaelic is spoken by a small number of Scots, more of whom speak various dialects of Lallans. Far to the north are the Orkney Islands and then Shetland, which were Viking Kingdoms and owe more allegiance to Norway, than even the Scots capital in Edinburgh, while London is 800 or so miles away. Tucked under the Normandy peninsula in France are the Channel Islands, known as a Crown Peculiar, and where French was spoken originally, and are largely self governing.
That is only a short tip of the iceberg to the British Isles. Ireland or Eire gained independence from England in 1921 after several centuries of trying to secede. Many Catholics in England usually have Irish or Polish ancestry, though the Polish connection dates from WWII and the 1940s onwards.
I will bore my readers no longer, except to say that a glance at a globe or map showing Britain does not reveal the complexity of the people and places with this archipelago. The governance of Britain has long been a question of divide and rule, and this is not an historical artefact but continues in modern times. Inspirational I suspect for many writers and budding authors.