On the earliest Latin translations of Greek astronomical and astronomical texts; after a discussion of the reintroduction of Greek into Western Europe, from Theodore of Tarsus' school at Canterbury to Pope Sylvester II and Hermann von Reichenau, this monograph discusses the manuscripts and variants of four authors: The collection under the name of Alchandreus (in part translated from the Syriac), containing seven or eight treatises, including the Letters of Petosiris and a letter from Alchandreus to Alexander; the dialogue between Nimrod (founder of astronomy as well as hunting) and his student Joatan; the Canon of Claudius Ptolemy, in Theon's edition; and an original compilation of astronomical quotations from classical sources in Latin as well as Greek.