Illustration of the Polish astronomer Nicolaus Copernicus (1473-1543). Copernicus claimed that the Universe was centred on the Sun and from 1512 developed a full mathematical model for this heliocentric theory. This system contrasted with that described by Ptolemy over a thousand years before, which held that the Universe was Earth-centred. The Ptolemaic system had become the doctrine of the Roman Catholic church. Copernicus, fearing persecution, delayed publication of his book, 'The Revolution of the Heavenly Spheres', until 1543. The book was banned by the Roman Catholic church from 1616 until 1835.