Back in the days of the Hapsburg Empire, there was a town in Bohemia called Budweis. The people in that town were called Budweisers and the town had a brewery which produced beer with the same name -- but different from the American Budweiser.
Like many communities in Bohemia during that era, Budweis had people of both Czech and German ancestries, speaking different languages, though many were also bilingual. They got along pretty well and most people there thought of themselves as Budweisers, rather than as Czechs or Germans. But that would later change -- for the worse -- not only in Budweis, but throughout Bohemia.
The mayor of Budweis spoke both Czech and German but refused to be classified as a member of either group. His point was that we are all Budweisers.
As with virtually all groups in virtually all countries and in virtually all eras, there were differences between the Germans and the Czechs. Germans were more educated, more prosperous, and more prominent in business and the professions.
The German language at that point had a much wider and richer literature, the Slavic languages having acquired written versions centuries later than the languages of Western Europe. Educated people of whatever ethnicity were educated in German.
Those Czechs who wished to rise into the upper echelons, whether in business, the military, or the professions, had to master the German language and culture, in order to fit in with those already at the higher levels.
People on both sides learned to live with this situation and Czechs were welcomed into the German cultural enclaves when they mastered that culture. In Budweis, they could all be Budweisers.
As in so many other countries and in so many other times, the rise of a newly educated intellectual class in the 19th century polarized the society with ethnic identity politics. All over Bohemia, the new Czech intelligentsia urged Czechs to think of themselves as Czechs, not Bohemians or Budweisers or anything else that would transcend their ethnic identity.
Demands were made that street signs in Prague, which had been in both Czech and German before, now be exclusively in Czech. Quotas were demanded for a certain percentage of Czech music to be played by the Budweiser orchestra.
If such demands seem petty, their consequences were not small. People of German ancestry resisted ethnic classifications but the Czech intelligentsia insisted and Czech politicians went along with the trend on many issues, large and small.