This educational video demonstrates the diversity of European languages and explains how this diversity provides insight into the history or war, migration and nationalism that shaped the continent. The video is in German but it provides English subtitles if you need them.
It also explains how dialects mingle with one another and are not always mutually intelligible and that border areas where multiple languages are spoken can give rise to new dialects. He has to explain this in the video because the complexity of linguistic diversity in Europe cannot be adequately portrayed in a simple map.
He even explains how our understanding of and appreciation of languages in Europe determines our attitude to them and their legitimacy in the eyes of Europeans as a whole. He compares Hebrew, the widely acknowledged language of Israel which was successfully revived after being dead for centuries, with the more recently deceased Cornish language, which is not widely recognised.
Across Europe there are all kinds of minority languages that are not seen as important, and which are expected to die off, while other languages, which are not necessarily spoken by more people, are protected by law and recognised as national languages. The video explains that the history of language in Europe is also a history of power relations, and understanding why a language is spoken in any give region depends on your knowledge of the history that promoted that language.