Both Masha’allah, and his younger contemporary Sahl (Zael) descended from a Jewish settlement at Marw, the capital of Khorasan, in Persia (a.k.a. Merv: equates to modern Afghanistan). They moved to Arabia to act as court astrologers and help establish centres of learning at the new capital city of Baghdad, following the conquest of Al Mansur in the 8th century. Their early background gave them distinct advantages in the translation of Greek Hellenistic texts since Marw was a predominantly Greek colony which lay on a trade route from Alexandria and acted as an important outpost for Hellenism. Therefore, Masha’allah and Sahl (who refers to Masha’allah frequently), became perfect transmitters of the Hellenised Arabian astrological texts which were later conveyed to medieval Europe.
As a young man Masha’allah helped elect the time of Baghdad’s formal foundation in 762, and he lived long enough to serve four succeeding caliphs, each of whom continued to develop the ‘House of Wisdom’ as a centre of translation and transmission of knowledge and science. Of all the philosophers of the era, he is described as being “the leading person for the science of judgements of the stars” (Al Nadim, Fihrist, p.650). He wrote numerous works on astrology in Arabic which were later translated into Latin to help establish the principles of Medieval astrology.