940
Year 940 was a leap year starting on Wednesday of the Julian calendar.
Events
By place
Europe
- The tribe of the Polans begins the construction of the following fortified settlements in Greater Poland. The Piast Dynasty under Duke Siemomysł gains control over other groups of Polans along the Upper Vistula, and establishes their rule around Giecz.
Japan
- March 25 - Taira no Masakado, the self-proclaimed "New Emperor", is subdued by local rivals who revolt against his rule. His forces are defeated by his cousin, Taira no Sadamori, in Shimōsa Province. Masakado's head is brought back to Emperor Suzaku in Tokyo.
By topic
Literature
- Saadia Gaon, a Jewish rabbi and philosopher, compiles his Siddur in Arabic and synagogal poetry in modern-day Iraq.
Religion
- Narita-san, a Shingon Buddhist temple, is founded in Chiba.
Births
- June 10 - Abu al-Wafa' Buzjani, Persian mathematician and astronomer
- Abdollah ibn Bukhtishu, Syrian physician and scientist
- Abu-Mahmud Khojandi, Persian astronomer and mathematician
- Abū Sahl al-Qūhī, Persian mathematician and physicist
- Adelaide-Blanche of Anjou, French queen and regent
- Al-Baqillani, Muslim theologian and jurist
- Baldwin III, Frankish nobleman
- Chavundaraya, Indian general, architect and poet
- Damian Dalassenos, Byzantine governor
- Eadwig, king of England
- Ferdowsi, Persian poet and author
- George El Mozahem, Egyptian martyr and saint
- Géza, Grand Prince of the Hungarians
- Guy, margrave of Ivrea
- Henry III, duke of Bavaria
- Leopold I, margrave of Austria
- Lothair I, margrave of the Nordmark
- Notker of Liège, French bishop and prince-bishop
- Sulayman al-Ghazzi, Arab poet and bishop of Gaza
- Subh of Córdoba, mother and regent of Hisham II
- Thorgeir Ljosvetningagodi, Icelandic lawspeaker
- Vijayanandi, Indian mathematician and astronomer
- Willigis, German archchancellor and archbishop
- Wulfhilda of Barking, English nun and abbess
Deaths
- March 25 - Taira no Masakado, Japanese nobleman and samurai
- May 12 - Eutychius, patriarch of Alexandria
- June 7 - Qian Hongzun, heir apparent of Wuyue
- July 4 - Wang Jianli, Chinese general
- July 20 - Ibn Muqla, Abbasid vizier and calligrapher
- August 5 - Li Decheng, Chinese general
- September 30 - Fan Yanguang, Chinese general
- November 8 - Yao Yi, Chinese chancellor
- November 14 - Abu'l-Fadl al-Bal'ami, Samanid vizier
- December 23 - Ar-Radi, Abbasid caliph
- December 25 - Makan ibn Kaki, Daylamite warlord
- Atenulf II, prince of Benevento and Capua
- Faelan mac Muiredach, king of Leinster
- Ibn Abd Rabbih, Moorish writer and poet
- Rajyapala, emperor of the Pala Dynasty
- Yang Lian, crown prince of Wu
- Zhao Guangyi, Chinese official and chancellor