“The clue to many contrasts in British geography,” wrote the geographer Halford Mackinder in 1902, “is to be found in the opposition of the south-eastern and north-western — the inner and outer faces of the land. Eastward and southward, between the islands and the continent, are the waters known to history as the Narrow Seas; northward and westward is the Ocean.” The happy conclusion he drew from this is that Britain has the best of both: “as liberty is the native privilege of an island people, so wealth of initiative is characteristic of a divided people.”
Tradition divides Britain diagonally, demarcating the south/east from the north/west, and imputes great significance to the contrast between these regions in the composition of British identity. For some, the tension between the two is creative, and Britain’s ingenuity benefits from facing both the Atlantic and Europe. Celtic was the term coined in the eighteenth century for the Atlantic-facing arc of Scots, Welsh, Manx and Irish…
This is of note:
Since 1821 the population of the Celtic arc of the north and west has declined as a proportion of the population of the United Kingdom, from 46 per cent in 1831, to 20 per cent in 1911, to 16 per cent in 2014, due to famine, independence and emigration. This is a configuration of the country which we have been losing for nearly two centuries.
That is from the rewarding Love of Country: A Hebridean Journey, by Madeleine Bunting.