Nicolaus Copernicus was born in Toruń in 1473, then part of the Kingdom of Poland. He studied at universities in Poland and Italy, pursuing law, medicine and mathematics, and served as a cathedral canon in Frauenburg, now Frombork. Alongside his ecclesiastical and administrative duties, he devoted years to the study of astronomy.

Most scholars of his age assumed that the Earth stood motionless at the centre of the universe. Copernicus investigated a different arrangement: the Earth rotated on its axis and travelled around the Sun, like the other planets. He initially shared his ideas with a limited circle. His major treatise, De revolutionibus orbium coelestium (On the Revolutions of the Heavenly Spheres), appeared only in 1543, shortly before his death.

His Sun-centred model did not immediately win general acceptance, and some elements of it were still inaccurate. Nevertheless, it changed the questions astronomers asked about the heavens. Later scientists, including Kepler and Galileo, developed the debate further. Copernicus died in Frombork in 1543. His name became associated with an intellectual revolution that challenged humanity's traditional place in the cosmos.