|Covid-19|The Song Dynasty governor of the bustling seaport of Quanzhou, Fujian, China, reports that the population of his city has reached 500,000 residents.
August–September (the eighth month of the Chinese calendar) – Wanyan Xiyin completes the design of the first version of the Jurchen script
January 16 – The Council of Nablus is held in the Kingdom of Jerusalem.
June 17 – At the Battle of Cutanda, the Aragonese troops of Alfonso I crush the Almoravid army.
November 25 – Sinking of the White Ship in the English Channel off Barfleur. King Henry I of England's only legitimate son, William Adelin, is among 300, many of them Anglo-Norman nobility, who drown.
Walcher of Malvern creates a system of measurement for the earth using degrees, minutes, and seconds of latitude and longitude.
Construction begins on Llandaff Cathedral in Wales.
Foundation of Freiburg in Breisgau.
Under admirals Abu Abd Allah ibn Maymum of Almeria and Isa ibn Mayum of Sevilla, the Almoravid fleet attacks the Christian kingdom of Galicia.
The Pseudo-Ingulf's Croyland Chronicle records Cornwall as a nation distinct from England.
Ioveta of Bethany, daughter of Baldwin II of Jerusalem
Louis VII of France (d. 1180)
November 25 – William Adelin, son of Henry I of England (sinking of the White Ship) (b. 1103)
September 3 – Gerard Thom (The Blessed Gerard), founder of the Knights Hospitaller (b. c. 1040)
Richard d'Avranches, 2nd Earl of Chester (b. 1094)
Year 1120 (MCXX) was a leap year starting on Thursday (link will display the full calendar) of the Julian calendar.