Abu Ma‘shar al-Balkhi, Latinized as Albumasar (also Albusar, Albuxar, Albumazar; full name Abū Maʿshar Jaʿfar ibn Muḥammad ibn ʿUmar al-Balkhī ابومَعْشَر جعفر بن محمد بن عمر بلخی; 10 August 787 – 9 March 886, AH 171–272),[3] was an early Persian[4][5][6] Muslim astrologer, thought to be the greatest astrologer of the Abbasid court in Baghdad.

[11] Abū Maʿshar is said to have died at the age of 98 (but a centenarian according to the Islamic year count) in Wāsiṭ in eastern Iraq, during the last two nights of Ramadan of AH 272 (9 March 866).

[14] It had significant influence on European medieval scholars, like Albert the Great who developed his own theory of tides based on a mix of both light and Abu Ma'shar virtue.

[1] Albumasar's "Introduction" (Kitāb al-mudkhal al-kabīr, written c. 848) was first translated into Latin by John of Seville in 1133, as Introductorium in Astronomiam, and again, less literally and abridged, as De magnis coniunctionibus, by Herman of Carinthia in 1140.

[16] Lemay (1962) argued that the writings of Albumasar were very likely the single most important original source for the recovery of Aristotle for medieval European scholars prior to the middle of the 12th century.