(1) Ja`far Muḥammad: b. Baghdad (Iraq), beginning of the ninth century; d. January or February 873; (2) Abū al-Qāsim Aḥmad: b. Baghdad, Iraq, beginning of the ninth century; d. Baghdad (Iraq), ninth century; (3) Ḥasan: b. Baghdad (Iraq), beginning of the ninth century; d. Baghdad (Iraq), ninth century. The 3 brothers, the three sons of Musā ibn Shākir, generally known under the single name of the Banū Mūsā, were among the most important scientists of Baghdad in the ninth century; they played a prominent role as private patrons of scientific translations and research, and excelled in the fields of astronomy, mechanics, and mathematics. [BEA, J. Casulleras]; also see 040-0, 040-1, 040-2; GAS V.252-3