banned for not counting the Aztec.
Okay, let's go with the 'we recognize you as a country' idea, just for laughs.
The territory of Cornwall was recognized by Wessex as a separate kingdom and the two clashed, resulting in Cornwall falling. The people of Cornwall, as was true of Whales, Scotland and Ireland, spoke a Celtic dialect. The people of Wessex spoke a Germanic dialect, predominantly a form of Anglo-Saxon. I will not argue that it didn't take some time, but the last person to natively speak that dialect died some time ago. Now it's like learning Latin, no one really uses it.
Francois de Premiere decided to unite France under him, requiring him to take in all the surrounding kingdoms. In the north, the Normans spread a mixture of Northern Germanic and Franconian and in the south there were a variety of latinizations of Franconian and Gallic, much like the strata of languages present today in Spain. In fact, many of the territory gained once belonged to factions which have since merged into Spain. He, in fact, united this kingdom and made his form of French the standard, even creating a political office to oversee the standardization of the language and its use. The other languages did take some time to die off and as new territories were acquired, they too had to be changed, but the use of French is very much standard and it is, to this day, carefully watched over to keep the use of slang and culturally absorbed terms to a minimum. The persistence of the government in maintaining this ideal has actually led to a great deal of unhappiness, both in the desire to develop a greater freedom of speech and to adapt to the growing influence of external powers.
I'm not saying it's common, but I think it's been occasionally pulled off. Especially in the case of near genocidal groups such as the Bennin and their subjugation of the Ife in Nigeria.
