Nicolaus Copernicus Albert, Alexander Jagiellon, and Sigismund I the Old. He was a friend and key advisor to each ruler, and his influence greatly strengthened the ties between Warmia and Poland proper. Watzenrode came to be considered the most powerful man in Warmia, and his wealth, connections and influence allowed him to secure Copernicus' education and career as a canon at Frombork Cathedral. Copernicus is postulated to have spoken Latin, German, and Polish with equal fluency; he also spoke Greek and Italian, and had some knowledge of Hebrew. The vast majority of Copernicus's extant writings are in Latin, the language of European
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