Sahl ibn Bishr al-Israili, more commonly; Rabban al-Tabari often known as Zahel or Zael (c. 786–845 ?) was a Syriac Christian (sometimes reported as Jewish)[1]astrologer,[2]astronomer and mathematician from Tabaristan. He was the father of Ali ibn Sahl the famous scientist and physician, who became a convert to Islam.[3]

His works

Sahl is believed to be the first who translated the Almagest of Ptolemy into Arabic.

Sahl ibn Bishr wrote in the Greek astrological tradition. Sahl's first five books were preserved in the translation of John of Seville (Johannes Hispanus) (c. 1090 – c. 1150). See the English translation by Holden. The sixth book deals with three thematic topics regarding the influences on the world and its inhabitants was translated by Herman of Carinthia. The work contains divinations based on the movements of the planets and comets.

  • The Introduction to the Science of the Judgments of the Stars. Translated by James Herschel Holden (Tempe, Az.: A.F.A., Inc., 2008)ix, 213 pp.

There are some books by Sahl ibn Bishr in Arabic such as:

  • Ahkam fi al-Nujum ("Laws of the Astrology")
  • Kitab al-ikhtiyarat 'ala al-buyut al-ithnai 'ashar ("Book of elections according to the twelve houses").
  • al-Masa'il al-Nujumiyah ("The astrological problems")


  1. ^ Prioreschi, Plinio (2001-01-01). A History of Medicine: Byzantine and Islamic medicine. Horatius Press. pp. 223–. ISBN 9781888456042. Retrieved 29 December 2014. 
  2. ^ "Astrology in Medieval Judaism - My Jewish Learning". Retrieved 29 December 2014. 
  3. ^ "JSTOR: An Error Occurred Setting Your User Cookie". JSTOR.