ABŪ SAHL B. NAWBAḴT, 2nd/8th century astrologer and author. The family of Nawbaḵt is said to have claimed descent from the Kayanid hero Gēv, the son of Gōdarz, but it is not known from what part of Iran Nawbaḵt himself came. Nawbaḵt first appears as an astrologer in the entourage of the second ʿAbbasid caliph, Manṣūr (136-58/754-75), under whose influence he converted from Zoroastrianism to Islam (Masʿūdī, Morūǰ VII, p. 290). He was associated with Māšāʾallāh in selecting the proper astrological moment (30 July 762) for laying the foundations of Baghdad (Yaʿqūbī, Boldān, p. 228; Bīrūnī, Āṯār al-bāqīya, pp. 270-71; idem, Chronology, pp. 262-63; Pingree, “al-Fazārī,” p. 104); and he advised Manṣūr concerning the revolt of Ebrāhīm in Šaʿbān-Šawwāl, 145/October, 762-January, 763 (Ṭabarī, III, pp. 317-18). Little else is known of Nawbaḵt save that his brief Resāla fī sarāʾer aḥkām al-noǰūm (“Epistle on the secrets of astrology”) survives in several manuscript copies (Ullmann, Geheimwissenschaften, p. 303, no. 3).

Nawbaḵt’s descendents became eminently successful in astrology, politics, and theology (Massignon; cf. Fehrest, p. 177). One of the more prominent members of the family was his son, Abū Sahl, whom he presented to Manṣūr as his successor in the post of court astrologer according to Yūsof b. Ebrāhīm, known as Ebn al-Dāya, who heard the story from Abū Sahl’s son Esmāʿīl (Ebn Abī Oṣaybeʿa, ʿOyūn II, p. 85; Ebn al-Qefṭī, Taʾrīḵ al-ḥokamāʾ, p. 409; Ebn ʿEbrī, Taʾrīḵ, p. 125). From this account we learn that Abū Sahl’s original name was Persian: Ḵᵛaršād Māh Ṭaymāḏā Mābāḏār Ḵosrevā Behšād (see Justi, Namenbuch, p. 226). The occurrence of the sun and the moon as the first two elements in his name probably indicates that Abū Sahl was born before Nawbaḵt’s conversion from Zoroastrianism. Abū Sahl continued to serve Manṣūr, accompanying him also, along with the court physician, Laǰlāǰ, on his last pilgrimage to Mecca in 775 (Ebn Abī Oṣaybeʿa, ʿOyūn II, pp. 84-85; Ebn al-Qefṭī, Taʾrīḵ, p. 439).

Abū Sahl’s career under the next two caliphs, Mahdī (775-85) and Hādī (785-86), remains obscure; but under Hārūn al-Rašīd (170-93/786-809) he took up a position in the Ḵezānat al-Ḥekma, where he was employed in translating Pahlavi books into Arabic. (See Fehrest, p. 274; Ebn al-Qefṭī, Taʾrīḵ, p. 255; these sources wrongly name him Abū Sahl al-Fażl, a mistake which led Ṣāʿed Andalūsī [Ṭabaqāt, ed., p. 60; tr., p. 117] to split him into two astrologers.) This translation activity was also pursued by other members of Nawbaḵt’s family (Fehrest, p. 244). Abū Sahl may perhaps be identical with the Sahl b. Nawbaḵt who is said to have versified for Yaḥyā b. Ḵāled Barmakī, the vizier of Mahdī and of Hārūn al-Rašīd until Ṣafar, 187/January-February, 803, the Arabic translation of the Kalīla wa Demna made by ʿAbdallāh b. Hellāl Ahwāzī for the same Yaḥyā in 160/776-77 (Kašf al-ẓonūn [Leipzig] V, p. 238). Abū Sahl probably died before the end of Hārūn al-Rašīd’s caliphate, as our sources do not mention him again.

Ebn al-Nadīm (Fehrest, p. 274), who is copied by Ebn al-Qefṭī (Taʾrīḵ, p. 225), lists seven books on astrology (none now extant) composed by Abū Sahl: 1. Ketāb al-nahmaṭān fi’l-mawālīd (“Book of the Nahmaṭān [?] concerning nativities”). A long extract, including an important history of the transmission of science and its preservation in Iran (see Pingree, Thousands, pp. 9-12) is preserved (Fehrest, pp. 238-39). 2. Ketāb afʿol al-noǰūm (“Book of the omens of the stars”). 3. Ketāb al-mawālīd: mofrad (“Book of nativities: solitary”). 4. Ketāb taḥwīl senī al-mawālīd (“Book of the revolutions of the years of nativities”). 5. Ketāb al-madḵal (“Book of the introduction”). 6. Ketāb al-tašbīh wa’l-tamṯīl (“Book of allegory and comparison”). 7. Ketāb al-montaḥel men aqāwīl al-monaǰǰemīn fi’l-aḵbār wa’l-masāʾel wa’l-mawālīd wa ḡayrehā (“Book of the plagiarist from the sayings of the astrologers concerning rumors, interrogations, nativities, etc.”). Various citations of Abū Sahl’s views on particular points found in astrological compendia presumably are derived from one or another of these works.


Abu’l-Faraǰ b. ʿEbrī, Taʾrīḵ moḵtaṣar al-dowal, Beirut, 1958.

Ebn Abī Oṣaybeʿa, ʿOyūn al-anbāʾ, 3 vols., Beirut, 1956-57.

Ebn al-Qefṭī, Taʾrīḵ al-ḥokamāʾ, ed. J. Lippert, Leipzig, 1903.

L. Massignon, “Nawbakht” and “Nawbakhtī,” EI1 III, p. 887.

C. A. Nallino, Raccolta di scritti editi e inediti V, Rome, 1944, pp. 199-201.

D. Pingree, “The Fragments of the Works of al-Fazārī,” JNES 29, 1970, pp. 103-23.

Idem, The Thousands of Abū Maʿshar, London, 1968.

Ṣāʿed al-Andalūsī, Ketāb ṭabaqāt al-omam, ed. L. Cheikho, Beirut, 1912; tr. R. Blachère, Paris, 1935.

Sezgin, GAS VII, pp. 100-01, 114.

Suter, Mathematiker, p. 3, no. 2 (Nawbaḵt), and p. 5, no. 7 (Abū Sahl).

M. Ullmann, Die Natur- und Geheimwissenschaften im Islam, Leiden, 1972, p. 303.

(D. Pingree)

Originally Published: December 15, 1983

Last Updated: July 21, 2011

This article is available in print.
Vol. I, Fasc. 4, p. 369

Cite this entry:

David Pingree, “ABŪ SAHL NAWBAḴT,” Encyclopædia Iranica, I/4, p. 369; an updated version is available online at http://www.iranicaonline.org/articles/abu-sahl-b (accessed on 31 January 2014).