Summary Claudius Ptolemy (c. 100-170 AD) is one of the most influential scholars of all time. While he is also the author of treatises on geography, optics and harmonics, his fame primarily stems from two works on the science of the stars, dealing with mathematical astronomy (the Almagest) and astrology (the Tetrabiblos). The Almagest and the Tetrabiblos remained the fundamental texts on the science of the stars for some 1500 years. Both were translated several times into Arabic and Latin and were heavily commented upon, glossed, discussed, and also criticised and improved upon, in the Islamic world and in Christian Europe. Yet, the reception of Ptolemy in medieval cultures is still to a large extent a terra incognita of the history of science. The Arabic and Latin versions of the Almagest and the Tetrabiblos are for the most part unavailable in modern editions, their manuscripts remain largely unexplored and, generally speaking, their history has never been systematically investigated. This volume gathers together fifteen contributions dealing with various aspects of the reception of Ptolemy's astronomy and astrology in the Islamic world and in Christian Europe up to the seventeenth century. Contributions are by Jos Bellver, Jean-Patrice Boudet, Josep Casulleras, Bojidar Dimitrov, Dirk Grupe, Paul Hullmeine, Alexander Jones, Richard L. Kremer, Y. Tzvi Langermann, H. Darrel Rutkin, Michael H. Shank, Nathan Sidoli, Carlos Steel, Johannes Thomann and Henry Zepeda. TABLE OF CONTENTS Introduction I. The Greek and Near-Eastern Traditions Alexander Jones, The Ancient Ptolemy Nathan Sidoli, Mathematical Methods in Ptolemy's Analemma Paul Hullmeine, Was there a Ninth Sphere in Ptolemy? Bojidar Dimitrov, 'Forte recte': Witnesses to the Text of Ptolemy's Tetrabiblos in Its Near Eastern Transmission II. The Arabic Tradition Johannes Thomann, The Oldest Translation of the Almagest Made for al-Ma'm?n by al-?asan ibn Quraysh: A Text Fragment in Ibn al-?al??'s Critique on al-F?r?b?'s Commentary Dirk Grupe, Th?bit ibn Qurra's Version of the Almagest and Its Reception in Arabic Astronomical Commentaries (Based on the presentation held at the Warburg Institute, London, 5 November 2015) Y. Tzvi Langermann, Revamping Ptolemy's Proof for the Sphericity of the Heavens: Three Arabic Commentaries on Almagest I.3 Jos Bellver, The Arabic Versions of J?bir b. Afla?'s al-Kit?b f? l-Hay'a Josep Casulleras, The Astrological Computations Attributed to Ptolemy and Hermes in Medieval Arabic Sources III. The Latin Tradition Henry Zepeda, Glosses on the Almagest by Campanus of Novara and Others in Paris, Biblioth que nationale de France, lat. 7256 Carlos Steel, A Discussion on Ptolemy's Authority. Henry Bate's Prologue to His Translation of Ibn Ezra's Book of the World Jean-Patrice Boudet, The Medieval Latin Versions of Pseudo-Ptolemy's Centiloquium: A Survey Michael H. Shank, Regiomontanus versus George of Trebizond on Planetary Order, Distances, and Orbs (Almagest 9.1) H. Darrel Rutkin, Optimus Malorum: Giovanni Pico della Mirandola's Complex and Highly Interested Use of Ptolemy in the Disputationes adversus astrologiam divinatricem (1496): A Preliminary Survey Richard L. Kremer, Longomontanus on Mars: The Last Ptolemaic Mathematical Astronomer Creates a Theory Indexes Index of Names and Work Titles Index of Modern Names Index of Manuscripts List of Contributors