Uriah 8 Ptolemy Very little is known about Claudius Ptolemy other than his work. He is believed to have lived somewhere around 100 - 170 AD. Claudius Ptolemy, is a mixture of the Greek Egyptian "Ptolemy" and the Roman "Claudius". This would indicate that he was descended from a Greek family living in Egypt and that he was a citizen of Rome, or vise versa . One of Ptolemy´s greatest achievements was the Almagest, which is a series of books that covers everything from pi to planetary theory. His theories were not superseded until a century after Copernicus presented his heliocentric theory in 1543. There were 13 books in all, and those books are what I will cover. The first two books covered cords of a circle. A chord is a line segment