How the impoverished, superstitious and ignorant people of the Dark Ages in Europe became citizens of new vital communities: Western Civilisation.
When Ancient Roman civilisation collapsed the then senile understanding of ancient Rome was replaced with that of the conquering barbarians who, while vigorous, were uneducated and superstitious; which was reflected in the social rule they adopted, that of the local bully: feudalism.
The grinding poverty obtained by feudalism did not readily allow the creation of spoilt (selfish) children, so over the succeeding generations the character of the majority of citizens slowly changed from mainly selfish to mainly unselfish.
While unselfish citizens are essential for a vital community, they are also dutiful so unwilling to challenge existing tradition, even though it was keeping everyone in poverty.
This was all changed with the appearance of the Black Death, which raged throughout Europe from 1347 until 1352, slaughtering the population and plunging society into chaos. People lost faith in existing beliefs as they proved incapable of explaining or halting the destruction of their community. Indeed, the small numbers of the survivors were insufficient for them to do things as they had previously. Tradition with its supporting superstitions was abandoned along with the limits demanded by previous notions of duty.
Freed from the rigid demands of the old traditions and forced to discover new ways of living, the survivors of the Black Death formed new communities with new traditions. Inevitably these new communities adopted techniques suited to their local climate and geography, so the new Europe became divided into new vital communities with their own unique understanding, hence their own unique language.
The birth of the English language, which was the birth of English communal understanding, was revealed by the publication of "The Canterbury Tales" by Geoffrey Chaucer (1342—1400) in the late fourteenth century.