To create the modern nation state a common language was often seen as a prerequisite.
Whereas in previous times there was a multiplicity of languages which were tolerated by a Ruler/Government, this no longer held as the concept of one highly centralised and organised state began to become the norm. Obviously, the dates and timelines for such changes differed from one European region to another, dependent on a number of differing factors. The story of Britain and France illustrates this very point.
The 'new' nation state, or at least its elite, began to see minority languages as belonging to a peasant underclass and therefore not worthy of attention. In some circumstances it was seen as a political threat to the state underpinning potential rebellion against it.
If we take England as a starting point, we know that pre 1066 the Saxon language, Old English, replaced that of Celtic, and that by the time of The Norman Conquest Anglo-Saxon was the standard language of the country, with the exception of Celtic speaking Cornwall and possibly the Celtic speaking far North West of Cumberland and Westmoreland. In the North East, around Yorkshire, Northumberland, and Durham the Old Norse language of the Viking settlers also existed, although it is thought that Old Norse and Old English (Saxon) were mutually intelligible and were certainly merging into one. It should be noted that the Saxon language which prevailed in England was the dialect of the dominant kingdom of Wessex.
Thus when the Norman French arrived they found a common language being spoken by nearly all in their newly acquired kingdom. They continued to speak Norman-French, although many became by necessity bilingual, as did many Saxons. By 1400 these two separate languages had melded into one; the language of Chaucer which we describe as Middle English.
England had become a unified state back in the 10th century under its Saxon kings and has remained so ever since, united from 1400 by a common language, which quickly became a second language to many native Cornish speakers. Cornish didn't finally succumb as a first language until the 18th century, Dolly Pentreath of Mousehole who died in 1777.
However, historically England grew to become Britain, absorbing in The Middle Ages Wales and Ireland and finally in 1603 Scotland. This introduced new languages which became in the context of an expanded England 'minority languages'. Indeed, in Scotland, Gaelic was always a minority language as in the centre, south, and east of the country English prevailed from a very early date. Gaelic was reduced to the area of the Western Highlands and Isles. It was already, before 1603, associated with a 'primitive' crofting culture and increasingly as a catholic one as well as Scotland embraced Protestantism from the mid 16th century. The unacceptable speaking of Gaelic arose after the failure of the Jacobite Rebellion of 1745. With mass emigration, the clan leaderships speaking English, teaching in schools in English, and Protestantism, the Gaelic language was in full retreat by the 19th century. Modern revival has helped keep the language alive but it is hardly, whatever the Parliament in Edinburgh might publicly say and even legislate for, 'commanding', in the phrase of the Scottish Government, equal respect to English'; it is rather a living relic.
Irish, like Scots Gaelic, was regarded by the English and Anglo-Irish as the language of the peasantry, the underclass. This was made worse at the time of The Reformation when the Irish peasantry remained doggedly catholic in a country ruled by a Protestant elite. As in Scotland, attempts were made to curtail the use of Irish in the 19th century when English became the language of instruction in many Irish schools. Although Irish hung on as a living language, particularly in the South West, even independence in the 1920s couldn't save it as a new national language of a newly independent Ireland. Despite subsequent attempts by the Irish Government to strengthen and broaden the use of Irish there was no way back in the increasingly global market place of the 20th century, and today Irish remains a minority language in the country. It is true that in 2003 Irish was recognised by the Government as an official language of the state, but this was more to do with sentimentalist revival than fact. A 2016 Survey found that c 10.5% of people spoke Irish on a daily or weekly basis, but only 4.2% could be regarded as regular speakers of the language. The figures in The North are even lower, being 6% and 0.2% respectively.
Of the nations comprising The United Kingdom and Northern Ireland, it is Wales which has maintained its language as a truly living one into the 21st century. This is largely because Wales converted to Protestantism at The Reformation and had a Welsh Bible. This religious grounding of the language was added to in the 18th century when Welsh was the language of the Welsh chapels. By being the language of church and chapel, it became the language of Sunday School, and therefore of literacy before state schools were established in the 1870s. There were attempts in Wales as in the other two Celtic nations to impose English via schools, but this failed to receive virtually any success, and today Welsh is compulsory as a taught language in the Principality's schools from the ages of 5 to 16, as well as a number of schools having their instruction in Welsh. There are no bilingual Welsh speakers left, but the language is in a better and more vibrant state than it has been for centuries. At present the Welsh Government is looking to expand Welsh as a teaching medium across all schools. Welsh is very much a living language and is closely associated with the rise of nationalist, or at least cultural, feeling in the country. Brexit is likely to strengthen rather than weaken the language.
And so to our nearest neighbour, France. France is obsessed by language, that is by the French language and by its purity. Since established by Cardinal Richelieu in 1624, the Academie Francaise has been the official body to preside over the language. It has 40 members. The average age of Academicians, known as The Immortals, is over 70, and they remain members for life. They include ex President Giscard d'Estang at 93 years old.
One might have though that such an institution would have been swept away at The Revolution, indeed it was for a short period, but revived under Napoleon, for he and others saw French as a way of instilling the ideas of the Revolution across the broad acres of France, with its myriad of languages and dialects. Today, increasingly, ordinary French men and women, are taking less notice of the Academy and developing the language in their own way. The latest clash between the elite Immortals and a sizeable part of the young French public is over gender neutral vocabulary. We all know, if only from school, that French has masculine and feminine words and spellings. This can strike the English speaker as very odd when, for example, words like person and celebrity are feminine. It is on this basis that the Academicians and others defend the status quo, arguing that grammatical gender is very different from biological gender. The Prime Minister is a supporter of the conservative position saying, 'The masculine form is a neutral form which should be used for terms liable to apply to women'. The BBC gives an example of how change operates, 'Take the rule that the masculine trumps the feminine when referring to a group that contains at least one man. In French 10 sisters and 1 brother are collectively happy/heureux - in a masculine way. Under proposed inclusive rules they would be hereux.euse.s'. At least the arguments over gender pronouns in English seem small beer by comparison.
This gender neutral row in France, brewing for a while, became centre stage when a Primary School textbook used the gender inclusive forms.
There are far more minority languages in France today than in any period of Britain's history. This mirrors the difficulty experienced in medieval France of establishing the 'state' of France, and the rule of the king in the numerous Provinces. Being an island with mountains in the north, defining England was a far easier task. Today, despite the presence of numerous minority languages, some experiencing, like Provencal, a renaissance, French remains the only official language of the state. France, like Britain, attempted in the 19th century to kill off these minority languages, primarily through education, and Like Britain largely failed. In the latter part of the 20th century and into the 21st France has rowed back from a position of total intolerance to one nearer the British model with Welsh and Gaelic. However, the political undercurrents flow faster than in England (If one assumes that Wales is unlikely to secede). Perpignan and area is increasingly militant over the use of Catalan as it comes to identify more with Barcelona than with Paris, Basque is in a very similar position. France is more laid back when it comes to Provencal (taught in state adult education classes), Breton, Picard, and Alsatian (although it would be going too far to say those with German ancestry in Alsace were quite as laid back as Paris). When, at The City Lit, I needed to book a hotel room in Strasbourg, I asked one of the language department who was fluent in French to make the booking for me. When she made it she spoke in German. She herself was German and regarded Strasbourg as a German city!
So the issue at the heart of the national debate about minority languages across Europe is firstly a diversity of cultures is to be welcomed whist at the same time the danger is that secessionist movements can use language as a political weapon.
Personal Afterword. I first took notice of minority languages in Britain when my wife and I were living in The Fylde of Lancashire. We used to fly over, from Blackpool airport, to the Isle of Man for weekend breaks. Staying in the town of Port Erin one weekend we noticed that there was a Manx folk concert in the hall next door. We went along and had a magical evening listening to traditional songs in their original Manx. But it was whilst we lived in The Fylde that the last native speaker of Manx, Ned Madrell, died in 1974. However, enough of the language had been saved on records and tape that it has gone from strength to strength as a minority language preserving with it something of the old traditional culture of the island. In 2015 there were 1,800 speakers out of a total population of 88,000 (many of them incomers), only 2% but nevertheless the largest number for over a century. Manx won't now disappear but neither will it replace or even challenge English. Indeed, like Wales, the Manx Government in 2017 established a Language Strategy.
Incidentally I referred above to the fact that we have recordings as to how Manx had been spoken but that was not the case in Cornwall and the pronunciation of Cornish today draws on Breton and Welsh so it may or may not be close to actual Cornish pronunciation of the past.
A final personal observation. One stout defence of Adult Education is how it has encouraged the learning of these minority languages. In Manchester I had a thriving Scots Gaelic course, taught by a Highlander and native speaker who just happened to be the Professor of French at Manchester University. At The City Lit we had numerous Welsh classes, Scots Gaelic, and Cornish classes. To my shame I never managed to establish a Manx or Irish course.