|Covid-19|November (or December) – Henry II of England, when word reaches him in France of Thomas Becket's latest actions, utters words that are interpreted by his followers as a wish for the archbishop's death.
December 29 – Thomas Becket, Archbishop of Canterbury, was assassinated in Canterbury Cathedral.
The Danes attack Estonia.
The city of Dublin is captured by the Normans.
The East Frisian island of Bant is broken up in a North Sea flood.
Palace guards massacre the civil officials at the Korean court and place a new king on the throne. The coup leaders abolish the privileges that have kept the aristocrats in power and appoint themselves to senior posts.
Earliest dating for the making of Cheddar cheese.
According to folklore, the Welsh prince Madoc sailes to North America in his ship the Gwennan Gorn and founds a colony.
Estimation: Fes in the Almohad Empire becomes the largest city of the world, taking the lead from Constantinople, capital of the Byzantine Empire.
May 9 – Valdemar II of Denmark (d. 1241) (alternative date is June 28)
August 8 – Saint Dominic, founder of the Dominicans (d. 1221)
Eustace the Monk, French pirate (d. 1217)
Isabella of Hainault, queen of Philip II of France (d. 1190)
Muqali, general of Genghis Khan
Approximate date – Fibonacci (Leonardo Pisano Bigollo), Pisan mathematician (d. 1240/50)
January 22 – Wang Chongyang, Chinese Daoist and co-founder of the Quanzhen School (b. 1113)
April 23 – Minamoto no Tametomo, Japanese samurai, first known person to die by seppuku (b. 1139)
November 18 – Albert I of Brandenburg (b. c. 1100)
November 23 or November 28 – Owain Gwynedd, King of Gwynedd (b. c. 1100)
December 29 – Thomas Becket, Archbishop of Canterbury (assassinated) (b. c. 1118)
Al-Mustanjid, Abbasid Caliph in Baghdad
Ruben II, Prince of Armenia (b. 1160)
Mstislav II of Kiev
Eliezer ben Nathan, Jewish poet and writer (b. 1090)
Odo, Viscount of Porhoet, co-ruler of the duchy of Brittany
Year 1170 (MCLXX) was a common year starting on Thursday (link will display the full calendar) of the Julian calendar.