Funny, I am watching "The last Kingdom" on Netflix, about Alfred and his attempt to unify England. I am sure it has only a passing acquaintance with the true history, but entertaining.
The Home Counties types are still trying to "unify England". The "Heptarchy" still exists.
I find one of the best predictors of local culture is the word for "church".
In French the word is "eglise"
In German it is "kirk"
In Britain kirk towns are found south of the Highland line and north of the Wash and the Humber.
West of the Highland line, in the Islands, Wales, Cornwall and Ireland you will find "kil", as in Kilkenny, "cil" and "coille" instead.
Church is an obvious derivative of kirk. The Scandinavians also use the word kirk.
Eglise and its variants can be found in Spain and Portugal, as well as in Scots and Irish Gaelic. Kil predates eaglais and may be tied to pre-Roman and pre-Christian religious sites.
Eglise is also derivative. The Greek word for church is ekklesia from which we get ecclesiastical by way of church Latin.
Italian for church is chiesa. Make of that what you will.
My own sense of European history is that Roman influence ended in the Third Century Crisis when Rome was abandoned and the Empire recentered itself on Byzantium, later to become Constantinople, known today through its Turkish pronunciation as Istanbul (Con = I, stan = stan, ople = bul). Greek, and Androvian christianity, I believe, to have been the dominant culture across the entirety of Europe from at least 250 AD. Rome was ruled from Milan and then Ravenna which were both subordinate to Constantinople. Germans were still going into battle as late as the Siege of Weinsberg in 1140 yelling "Lord have mercy" in Greek as their battle cry - "Kyrie eleison".
Modern Europe, in my view, dates from circa 800.
Charlemagne and his father Pippin.
Alfred of Wessex.
Popes Stephen, Paul I and Gregory.
Winfrid of Crediton, Alcuin and the Venerable Bede, chronicler not just of the English but of Western history. Winfrid and Alcuin were the preferred religious advisers for Pippin and Charlemagne. All were from Alfred's kingdoms.
A palimpsest is a parchment that has been used and then erased and reused. The practice was quite common during Bede's time due to the lack of paper and parchment.
Bede was very good at writing history on palimpsests.