Translated from the Arabic by Gerard of Cremona in Toledo between c. 1140 and 1175. The generally accepted date of 1175 for the translation has arisen from a misunderstanding of the colophon in MS Florence, BML, Plut. 89 sup. 45, which only implies that the translation was copied on 11 August 1175 by a certain master Thadeus the Hungarian (‘Expleta est dictio tertiadecima libri Ptholomei, et cum ea completur liber Almagesti latine vocatur vigil cura magistri Thadei Ungari anno domini millesimo CLXXV Toleti consumatis, anno autem Arabum quingentessimo LXX^o mensis octavi XI^o die translatus a magistro Girardo Cremonensi de Arabico in Latinum’). The translation thus existed by 1175, but it may have been made, or at least begun, long before that date, possibly as early as the 1140s or 1150s. Gerard used the two main Arabic translations that were available at the time, namely al-Ḥajjāj’s version and Isḥāq’s version. The Latin translation exists in two versions, an original version (Kunitzsch’s Class A) and a revised version (Class B) (see Kunitzsch, Der Sternkatalog, II, 1-10). One important characteristic of Class A is a mistake in the star catalogue, where the latitude of certain stars is given as 300 instead of 60 (reflecting the western and eastern values of the letter sīn respectively), as well as a number of mistakes which were fully corrected in Class B. Gerard’s translation is the source text of commentaries C.1.3, C.1.4, C.1.5, C.1.8, C.1.9, C.1.10, C.1.14, C.1.15, C.1.17, C.1.16 and C.1.21, and was also used in commentary C.1.6.

Note 1 Ptolemy’s star catalogue (VII.5-VIII.1) excerpted from Gerard’s translation appears independently from the Almagest in several contexts, most notably as the star catalogue of the Alfonsine tables, where all longitudes have been adjusted +17°08′ (see P. Kunitzsch, ‘The Star Catalogue Commonly Appended to the Alfonsine Tables’, Journal for the History of Astronomy 17 (1986), 89-98). The manuscripts containing this Alfonsine star catalogue have been ignored in the list below. Likewise, other star catalogues excerpted from the Almagest and adjusted for dates posterior to the Alfonsine tables (and possibly deriving from them) have been ignored. Two examples of these occur in the Ptolemaic MSS Melk, SB, 601 (olim 51), f. 112r-123v (adjusted for 1424), and Vatican, BAV, Pal. lat. 1376, f. 194r-207v (adjusted for 1444).

Note 2 Another section of the Almagest in Gerard’s translation which circulated independently is the second part of the preface containing 33 proverbs ascribed to Ptolemy (inc. ‘Hec sunt de disciplinis et sapientiis Ptolemei huius. Conveniens est intelligenti pro Deo verecundari cum ea que non sunt grata…’). This section occurs for instance in MSS Cesena, BCM, Piana 3.171, s. XIV, f. 3r; Munich, BSB, Clm 9683, s. XIII-XIV, f. 61vb-62rb; Munich, BSB, Clm 15723, s. XIV, f. 94r; Oxford, SJC, 188, s. XV, f. 96v; and Vatican, BAV, Pal. lat. 1046, s. XIV, f. 53rb-54va. These manuscripts have not been included in the list below and no attempt has been made to locate all of them.

Text ‘(Paris, BnF, lat. 14738) (1r-1v) [preface] Quidam princeps nomine Albuguafe in libro suo, quem scientiarum elect<ionem> et verborum nominavit pulcritudinem, dixit quod hic Ptholomeus fuit vir in disciplinarum scientia prepotens, preminens aliis, in duabus artibus subtilis, id est geometria et astrologia, et fecit libros multos — anno vite sue LXXVIIIº. Haec sunt de disciplinis et sapientiis Ptholomei huius: Conveniens est intelligenti pro Deo — propinque vero non dulcescunt. Liber hic precepto Maimonis regis Arabum — et motuum qui sunt in caelo conscripsit. In hoc autem libro sunt XIII distinctiones, in unaquaque quarum scientie huius capitula continentur, que in uniuscuiusque earum principio dicam. (1v-17r) [book i] In prima autem dictione sunt XIIII capitula… Capitulum XIIII de scientia quantitatis arcuum equationis diei qui elevatur in spera directa cum arcubus orbis signorum datis. Ecce ubi initium primi capituli prime dictionis dedit. Bonum, Scire, fuit quod sapientibus non deviantibus visum est cum partem speculationis a parte operationis diviserunt, que sunt due sapientie partes — speram rectam absque declinatione. Expleta est dictio prima. (17r-41r) [book ii] Incipit secunda <dictio> libri Almagesti Ptholomei Phludensis, cuius capitula sunt XIII … (17v) Capitulum primum de scientia habitabilium terre. Et post ea que narravimus in dictione prima Almagesti de forma tocius et communitate — ex eis que secuntur occidentem a loco altero. Expleta est dictio secunda libri Almagesti in qua sunt figure XX: arcus orbis signorum… et ad principium Arietis CCXCII XX. (41r-55v) [book iii] Dictio tercia libri Almagesti incipit, in qua sunt capitula X… (41v) Capitulum primum de scientia quantitatis longitudinis anni et numero dierum eius. Postquam declaravimus in his que precesserunt hanc distinctionem summam eorum que premittenda erant — et per motum suum diversum in tercia parte et octavo minuto Piscis fere. Expleta est dictio tercia Almagesti. Cum additis super annos… per quos intrabis in hunc librum (followed by a table: Ferie annorum – Reductio erarum). (55v-75r) [book iv] Dictio quarta libri Almagesti. Capitulum primum ex quibus… Capitulum primum ex quibus considerationibus oportet investigationes Lune. Iam narravimus et demonstravimus in dictione que est ante hanc totum quod contingit in motu Solis — (74v) has eclipses convenientes modo quem narravimus. (75r) Expletum undecimum capitulum quod est ultimum dictionis quarte Almagesti. (75r-93v) [book v] Dictio quinta libri Almagesti XIX capitula continens… Capitulum primum de artificio instrumenti ex armillis quo accipiuntur stelle et sciuntur loca earum in longitudine et latitudine. Inicium libri primi. Que vero accidunt ex applicatione Lune cum Sole in coniunctionibus et oppositionibus que sunt in eis ex eclipsibus — XXXV partes et sexta partis, et hoc est quod debuimus demonstrare. (93v-112r) [book vi] Dictio sexta Almagesti in qua sunt capitula XIII … Capitulum primum de coniunctionibus et impletionibus. Postquam sequitur quod iam precessit positio libri in applicationibus eclipsium que sunt Solis et Lune — (110v) et fines ini[ni]ciorum eclipsis et complementorum (followed by two figures and a table, f. 110v-111v). (112r) Expleta est dictio sexta. (112r-127r) [book vii] Capitulum primum de hoc quod longitudo… Capitulum primum et cum eo incipit dictio septima Almagesti Ptholomei de stellis fixis. Et postquam narravimus in dictionibus que hanc precedunt dictionem ea que accidunt in spera recta et in spera declivi — (118r) est minus illa quantitate et ita est descriptio tabularum (followed by the star catalogue, f. 118v-127r). (127v-140v) [book viii] Distinctio octava incipit cuius sunt capitula VI. Capitulum primum de affirmatione stellarum fixarum… (star catalogue, f. 127v-135v) … (136r) Capitulum secundum de modo orbis lactei nominati maiarati, id est arca. Loca vero stellarum fixarum secundum suum ordinem — ex eo quod est in figuris divisionis inclinationum Lune. Expleta est dictio octava libri Almagesti. (140v-157v) [book ix] Dictio nona et sunt in ea XI capitula… Capitulum primum libri noni Ptholomei in Almag<esto> de ordinibus sperarum Solis et Lune et quinque stellarum retrogradarum. Quantum fuit possibile aliquem loci de stellis fixis et speciebus scientie habitudinum earum secundum quantitatem — addunt VI partes Libre que fuerunt in tempore considerationis super partem unam et sextam partis Libre. Explicit dictio nona. (157v-168r) [book x] Incipit dictio decima in qua sunt capitula decem… Capitulum primum libri decimi in declaratione longitudinis longioris stelle Veneris. Radices secundum quas agitur in stella Mercurii et quantitates diversitatum et preter illud etiam summam motuum et revolutionium eius — posito locorum super XVI partes et XL minuta Cancri et illud est quod voluimus ostendere. Expleta dictio decima libri Ptholomei qui dicitur Almagesti. (168r-184r) [book xi] Incipit dictio undecima in qua sunt XII capitula… Incipit capitulum primum libri duodecimum (!) Almagesti. Et quia iam demonstravimus revolutiones motuum in stella Martis et radices eius — (184r) in illa hora pervenimus enim ad locum eius super quem videtur orbis signorum. Expleta est dictio undecima libri Almagesti. (184r-197r) [book xii] Dictio duodecima in qua sunt IXa (!) capitula… (184v) Incipit capitulum primum libri duodecimi Almagesti Ptholomei. Postquam demonstrate sunt iste res tunc iam sequitur eas etiam consideratio in eo quod est cuiusque stellarum V erraticarum — et in quinta longitudines eius vespertinas, et hec est forma tabule (followed by the table). (197r-211r) [book xiii] Capitulum primum in radicibus secundum quas agitur in cursibus stellarum V erraticarum in latitudine… Capitulum primum in… (end of sentence missing) (197v) Et quia remanserunt apud nos consequenter in scientia stellarum V erraticarum due res quarum una est scientia eius quod provenit ex cursibus in latitudine — et abbreviationem arrogantiam et collaudationem. Tunc iam sequitur et honestum est ut ponamus hic finem libro. Expleta est dictio XIIIa libri Ptholomei et cum ea completur liber Almagesti de disciplinalibus. Laus Deo. Amen.’

Bibl. F. Wüstenfeld, Die Übersetzungen Arabischer Werke in das Lateinische seit dem XI. Jahrhundert, Göttingen, 1877, 64 (no. 22); M. Steinschneider, Die europäischen Übersetzungen aus dem Arabischen bis Mitte des 17. Jahrhunderts, Wien, 1904, 19 (no. 36); C. H. Haskins, Studies in the History of Mediaeval Science, Cambridge, 1927 (2^nd ed.), 104-108; M. Alonso, ‘La tercera version del Almagesto en el siglo XII’, Al-Andalus 10 (1945), 453-454; F. J. Carmody, Arabic Astronomical and Astrological Sciences in Latin Translation. A Critical Bibliography, Berkeley-Los Angeles, 1956, 15 (no. 1); P. Kunitzsch, Der Almagest – Die Syntaxis Mathematica des Claudius Ptolemäus in arabisch-lateinischer Überlieferung, Wiesbaden, 1974, 83-112; P. Kunitzsch, Der Sternkatalog des Almagest. Die arabisch-mittelalterliche Tradition, 3 vols, Wiesbaden, 1986-1991, II; P. Kunitzsch, ‘Die Überlieferung des Almagest, griechisch-arabisch-lateinisch’, in Lingua restituta Orientalis. Festgabe für Julius Assfalg, ed. M. Görg, Wiesbaden, 1990, 203-210: 208-210; P. Kunitzsch, ‘Gerhard von Cremona als Übersetzer des Almagest’, in Festgabe für Hans-Rudolf Singer, zum 65. Geburtstag am 6. April 1990, ed. M. Forstner, Frankfurt/Main-Bern-New York-Paris, 1991, 347-358 (reprinted in P. Kunitzsch, Stars and Numbers. Astronomy and Mathematics in the Medieval Arab and Western Worlds, Aldershot, 2004, II); P. Kunitzsch, ‘Gerard’s Translations of Astronomical Texts, Especially the Almagest’, in Gerardo da Cremona, ed. P. Pizzamiglio, Cremona, 1992, 71-84 (reprinted in P. Kunitzsch, Stars and Numbers. Astronomy and Mathematics in the Medieval Arab and Western Worlds, Aldershot, 2004, I); C. Burnett, ‘The Coherence of the Arabic-Latin Translation Program in Toledo in the Twelfth Century’, Science in Context 14 (2001), 249-288: 277 (no. 22) (reprinted in C. Burnett, Arabic into Latin in the Middle Ages. The Translators and their Intellectual and Social Context, Farnham-Burlington, 2009, VII); C. Burnett, ‘Why Study Ptolemy’s Almagest? The Evidence of MS Melbourne, State Library of Victoria, Sinclair 224’, La Trobe Journal 81 (2008), 127-143; J. N. Crossley, ‘Ptolemy’s Almagest: Its Dates and the Dating of Oxford, All Souls College, ms. 95’, La Trobe Journal 81 (2008), 118-126; C. Burnett, ‘‘Ptolemaeus in Almagesto dixit’: The Transformation of Ptolemy’s Almagest in its Transmission via Arabic into Latin’ in Transformationen antiker Wissenschaften, eds G. Toepfer, H. Böhme, Berlin-New York, 2010, 115-140; P. Kunitzsch, ‘Translators’ Errors in the Almagest, Arabic and Latin’, in Adorare caelestia, gubernare terrena: Atti del colloquio internazionale in onore di Paolo Lucentini (Napoli, 6-7 Novembre 2007), eds P. Arfé, I. Caiazzo, A. Sannino, Turnhout, 2011, 283-293; H. Zepeda, The Medieval Latin Transmission of the Menelaus Theorem, PhD dissertation, University of Oklahoma at Norman, 2013, 28-61, 130-144; C. P. E. Nothaft, ‘A Reluctant Innovator: Graeco-Arabic Astronomy in the Computus of Magister Cunestabulus (1175)’, Early Science and Medicine 22 (2017), 24-54; H. Zepeda, ‘Glosses on the Almagest by Campanus of Novara and Others in Paris, Bibliothèque nationale de France, lat. 7256’, in Ptolemy’s Science of the Stars in the Middle Ages, eds D. Juste, B. van Dalen, D. N. Hasse, C. Burnett, Turnhout, 2020, 225-244; S. Zieme, ‘Gerard of Cremona’s Latin Translation of the Almagest and the Revision of Tables’, Journal for the History of Astronomy 54 (2023), 3-33; S. Georges, Glosses as a Source for the History of Science. The Case of Gerard of Cremona’s Translation of Ptolemy’s Almagest (forthcoming).

Modern ed. None, except for Book I, ed. E. Nicolai, La tradizione greco-latina e arabo-latina del I libro dell’Almagesto. Saggio di analisi e traduzione, PhD dissertation, Università di Padova, 2010, 201-224 (from ed. Venice 1515); the preface, ed. and tr. Burnett, ‘Ptolemaeus in Almagesto’, 125-130; chapter I.1 in its three versions, ed. Burnett, ‘Ptolemaeus in Almagesto’, 131-139; the star catalogue in VII.5-VIII.1, ed. Kunitzsch, Der Sternkatalog, II; the Menelaus theorem in I.12, ed. Zepeda, The Medieval Latin Transmission, 361-371, and a selection of marginalia in connection with the Menelaus theorem from nine manuscripts, ed. Zepeda, The Medieval Latin Transmission, 372-432.