All his studies were in in latin, latin was the official administrative language of Poland, he never wrote a single scientific work in polish or german languages.
Probably correct until we find some lost manuscripts. My point was this; Copernicus was an astronomer, a churchman, a physician by training, an economist, statesman, soldier, poet and even a painter. He had good knowledge of various mechanics, surveying, etc. All of this done under the Polish king, for the Polish king, by the Polish king, with the Polish king.........
As we know, the siege of Olsztyn (Allenstein) proved who he was and what side he thought himself being (on).