Almagest

With its rare Arabic copy of the Almagest, this manuscript is a clear example of the intercultural transmission of Ptolemy’s text. A colophon (fol. 185r) identifies the copyist as the Muslim astronomer Aḥmad ibn Aḥmad ibn Salāmah Sanhaja, who produced this manuscript for his Jewish teacher, Qursunna al-Isrāʼīlī, astronomer to Pedro IV of Aragon. It is dated according to Muslim, Jewish, and Christian calendars (783, 5141, and 1381).

Originally called Μαθηματικὴ Σύνταξις (Mathematical Syntaxis), the Almagest summarizes ancient astronomy in thirteen books, including planetary orbits, eclipses, and retrograde motion. The Almagestwas translated into Arabic in the ninth century; indeed, its English name derives from the Arabic “al-majisṭī.” The most influential Latin translation was produced by Gerard of Cremona in 1175, while he was employed at the Toledo School of Translators.