Nicolaus Copernicus

Nicolaus Copernicus (1473–1543) was an astronomer who placed the Sun, not the Earth, at the centre of the universe. Born at Toruń, he was educated by his maternal uncle Lucas Watzenrode, later Bishop of Warmia. He studied at Kraków, Bologna and Padua, took a canon-law doctorate at Ferrara in 1503, and served his uncle as secretary and physician.

A canon of Warmia from 1497, before 1514 he circulated the Commentariolus, an outline of his heliocentric system. From 1516 to 1521 he ran Olsztyn and directed its castle's defence against the Teutonic Knights.

He hesitated to publish until 1539, when Georg Rheticus joined him and promoted his work. De revolutionibus orbium coelestium was printed at Nuremberg in 1543 with an unsigned preface calling its hypotheses mere calculation tools. He died on 24 May 1543, legend says with the finished book placed in his hands. It set off the Copernican Revolution.