Nicolaus Copernicus is known that Copernicus knew Polish on a par with German and Latin. Historian Michael Burleigh describes the nationality debate as a "totally insignificant battle" between German and Polish scholars during the interwar period. Polish astronomer Konrad Rudnicki calls the discussion a "fierce scholarly quarrel in ... times of nationalism" and describes Copernicus as an inhabitant of a German-speaking territory that belonged to Poland, himself being of mixed Polish-German extraction. Czesław Miłosz describes the debate as an "absurd" projection of a modern understanding of nationality onto Renaissance people, who identified with their home territories rather than with a nation. Similarly,
Nicolaus Copernicus several Kraków astronomers with whom he collaborated in 1515–30 in observing eclipses. Tycho Brahe would include a fragment from the "Commentariolus" in his own treatise, "Astronomiae instauratae progymnasmata", published in Prague in 1602, based on a manuscript that he had received from the Bohemian physician and astronomer Tadeáš Hájek, a friend of Rheticus. The "Commentariolus" would appear complete in print for the first time only in 1878. In 1510 or 1512 Copernicus moved to Frombork, a town to the northwest at the Vistula Lagoon on the Baltic Sea coast. There, in April 1512, he participated in the election of Fabian