# al-Hajjaj ibn Yusuf ibn Matar

- id: al-hajjaj
- name in original script: الحجاج بن يوسف بن مطر
- dates: fl. 786-833, Baghdad
- roles: translator, reviser

The first known Arabic translator of Euclid's Elements and one of the first of the Almagest. He translated Euclid once for the Barmakid vizier Yahya ibn Khalid and again, leaner, for al-Ma'mun, saying he had cut the superfluities and corrected the errors.

## Crossings

- c. 786–805: Elements into Arabic (translator) [attested]
- c. 813–833: Elements into Arabic (reviser) [attested]
- 827–828: Almagest into Arabic (translator) [attested]

## Sources

- Hockey, Thomas et al. (eds.) (2007). Biographical Encyclopedia of Astronomers (entries: Fazari, Khwarizmi, Majriti, Hajjaj ibn Yusuf ibn Matar).
- Murdoch, John E. (1971). Euclid: Transmission of the Elements.