I'm reading a noir mystery called Death in Breslau, by a Polish novelist named Marek Krajewski, which I bought because it's where my father was born.
The 1900 census listed 5,363 people (just over 1% of the population) as Polish speakers, and another 3,103 (0.7% of the population) as speaking both German and Polish. The population was 58% Protestant, 37% Catholic (including at least 2% Polish) and 5% Jewish (totaling 20,536 in the 1905 census). The Jewish community of Breslau was among the most important in Germany, producing several distinguished artists and scientists.
My father was born in 1906, halfway between the founding of the German Empire in 1871 and the early Weimar Republic. In those days, I've read, relations between Protestants, Catholics, and Jews were more open than they became after WWI. Jews were a part of a broad urban community where they were largely equal but also able to remain Jewish.
His family moved to Berlin, 200 miles to the west, when he was 3, & as far as I know, he never went back before being forced to leave the country in 1939.
Breslau, renamed Wroclaw, has been part of Poland since WW II.