940 in history

Born in 940

Jun 10 Abū al-Wafā' Būzjānī a Persian mathematician and astronomer who worked in Baghdad. He made important innovations in spherical trigonometry, and his work on arithmetics for businessmen contains the first instance of using negative numbers in a medieval Islamic text
Nov 14 Abu'l-Fadl al-Bal'ami a Samanid statesman, who served as the vizier of Nasr II from 922 to 938.
Dec 25 Makan ibn Kaki a Daylamite military leader active in northern Iran in the early 10th century. He became involved in the succession disputes of the Alids of Tabaristan, and managed to establish himself as the ruler of Tabaristan and Gurgan for short periods of time, in competition to other Daylamite warlords such as Asfar ibn Shiruya or the Ziyarid brothers Mardavij and Vushmgir. He alternately opposed and secured support from the Samanid governors of Khurasan, and eventually fell in battle against a Samanid army

Died in 940

May 11 Patriarch Eutychius of Alexandria the Greek Orthodox Patriarch of Alexandria. He is known for being one of the first Christian Egyptian writers to use the Arabic language. His writings include his chronicle Nazm al-Jauhar , otherwise known by its Latin title, Eutychii Annales
Jul 20 Ibn Muqla an Persian official of the Abbasid Caliphate who rose to high state posts in the early 10th century. His career culminated in his own assumption of the vizierate at Baghdad thrice, in 928–930, 932–933 and 934–936. Unable to successfully challenge the growing power of regional emirs, he lost his position to the first amir al-umara, Ibn Ra'iq, and died in prison. He was also a noted calligrapher
Dec 23 Ar-Radi the Abbasid Caliph in Baghdad from 934 to his death at the age of thirty-three in 940.