Nicolaus Copernicus, a canon born in Toruń (Royal Prussia, Poland), publishes in 1543 De revolutionibus orbium coelestium, proposing that the Sun — not the Earth — is the center of the solar system, and that the Earth rotates on its axis and revolves around the Sun. The book was published the same year he died. Aristarchus of Samos had proposed heliocentrism in the 3rd century BC, but without the mathematical apparatus Copernicus develops. The Copernican revolution is the starting point of modern astronomy and the break with the Ptolemaic cosmology that dominated for 1,400 years. The Catholic Church placed De revolutionibus on the Index of Forbidden Books in 1616, 73 years after its publication.