English as a Political tool

In a brief analysis of the "European Question and National Interest" , Professor Jeremy Black makes an interesting comment about 100 year long war between France and England.
In the 1330s, as France and England drifted towards war it became rather awkward for the aristocracy to continue with what we would now call international and francophile outlook and behaviour.
In particular, the question of the language became acute. The use of English as it had developed from mixed Anglo-Saxon and Norman roots became a matter of patriotic political tool.

    “In 1344, it was claimed before the House of Commons, an important and indicative choice of location, that Philip VI of France was ‘fully resolved … to destroy the English language, and to occupy the land of England’. As the lower classes spoke English anyway, it was only a shift by the upper classes that was at issue.”
There is but a short step from that to the first two great literary works in English:ohn Gower’s Confessio Amantis and, above all, Geoffrey Chaucer’s Canterbury Tales.