940

Events 

 Saadia Gaon makes his siddur (Jewish prayer book) in Iraq.
 Narita-san Temple is founded in Chiba, Japan.
 The Liao Dynasty stops the rule that a younger sister replace an older sister who died in marriage.

 Births 

 Abu'l-Wafa, Iranian mathematician
 Brian Boru, high king of Ireland

 Deaths 

 July 20 – Ibn Muqla, Abbasid vizier and calligrapher
 December 25 – Makan ibn Kaki, Dailamite warlord
 Taira no Masakado, leader of the Taira Clan