Ptolemy, Ptolomaeus Almagestus (Almagest), translated by Gerardus Cremonensis, copied c 1200–25 in northern Italy, Rare Books collection

Greek-born Claudius Ptolemaeus, better known as Ptolemy, lived in Alexandria in Egypt and worked there as philosopher, astronomer, mathematician and geographer. He wrote a number of monumental works including this text on astronomy, composed c 130 CE. The geocentric (earth at the centre) Ptolemaic understanding of the universe guided all Islamic and European astronomers until 1543, when it was challenged by Nicolaus Copernicus’ heliocentric theory, which described the planets revolving around the sun.

This book (like all our medieval manuscripts) is available to view and download in high resolution via the 'View a full-size version of this item' link, on the right.