# Almagest

- id: almagest
- original title: Μαθηματικὴ Σύνταξις / Mathēmatikē Syntaxis
- author: Ptolemy
- language: Greek
- composed: c. 150, Alexandria
- field: astronomy

Ptolemy's mathematical model of the heavens, completed in Alexandria around 150 CE. Even its common name records the crossing: Almagest is Latin for al-Majisti, the Arabic rendering of a Greek superlative, 'the greatest'.

## The chain

- **827–828** Greek -> Arabic, translation as "المجسطي" [attested]
  al-Hajjaj ibn Yusuf ibn Matar (translator), al-Ma'mun (patron), Baghdad
  The earliest surviving Arabic Almagest, dated 212 of the Hijra. Lost Syriac and 'old Arabic' versions of around 800, promoted by the Barmakids, preceded it.
  Evidence: Ptolemaeus Arabus et Latinus project 2023 (work entry for the al-Hajjaj version); Kunitzsch 1974
  - **c. 1140–1175** Arabic -> Latin, translation as "Almagesti" [attested]
    Gerard of Cremona (translator), Toledo
    Completed by 1175: a colophon records a copy made on 11 August of that year, and the work may have begun decades earlier. This edge follows the al-Hajjaj version for Books I-IX; Kunitzsch showed that Books X-XIII and the star catalogue follow the Ishaq-Thabit recension instead. A direct Greek-to-Latin translation made in Sicily in the mid-12th century circulated little.
    Evidence: Ptolemaeus Arabus et Latinus project 2023 ('existed by 1175, but may have been made long before'); Kunitzsch 1974 (Books I-IX from al-Hajjaj, Books X-XIII and the star catalogue from Ishaq-Thabit)
- **c. 879–890** Greek -> Arabic, translation [attested]
  Ishaq ibn Hunayn (translator), Baghdad
  The second surviving Arabic translation, made half a century after al-Hajjaj's.
  Evidence: Ptolemaeus Arabus et Latinus project 2023
  - **c. 890–901** Arabic -> Arabic, revision [attested]
    Thabit ibn Qurra (reviser), Baghdad
    Completed before Thabit's death in 901. The Ishaq-Thabit Almagest became the standard eastern text.
    Evidence: Ptolemaeus Arabus et Latinus project 2023

## Worth knowing

One book pulled the most prolific translator of the Middle Ages across Europe. Gerard of Cremona's students wrote that he went to Toledo 'for love of the Almagest, which he could not find at all among the Latins', learned Arabic there, and stayed for life. Daniel of Morley, who heard him dispute in public at Toledo, identifies him in passing as the man who Latinized the Almagest 'with Galib the Mozarab interpreting'.

## Sources

- Ptolemaeus Arabus et Latinus project (2023). Work entries for the Arabic and Latin Almagest translations. Bavarian Academy of Sciences.
- Kunitzsch, Paul (1974). Der Almagest: Die Syntaxis Mathematica des Claudius Ptolemäus in arabisch-lateinischer Überlieferung. Harrassowitz.
- Lemay, Richard (1978). Gerard of Cremona. Dictionary of Scientific Biography, vol. 15 supplement.

Confidence grades: attested (named in the medieval record or settled in scholarship), probable (standard view with real uncertainty), disputed (scholars disagree).