1180

Events

September 24 – Emperor Manuel I Komnenos dies in Constantinople after a 37-year reign. He is succeeded by his 11-year-old son, Alexios II Komnenos, who will reign briefly as emperor of the Byzantine Empire under the regency of his mother, Maria of Antioch. Maria assumes power as regent and takes as her advisor and lover, Alexios Komnenos (protosebastos), a nephew of Manuel I, which causes scandal and unrest among the Byzantine populace.

January 13 – Henry the Lion, Duke of Saxony and Bavaria, is stripped of his duchies and all his imperial fiefs at an Imperial Diet in Würzburg for violating the king's peace. On April 13, Emperor Frederick I Barbarossa issues the Gelnhausen Charter, formally dissolving Henry's former domains. A portion of Saxony is reorganized as the Duchy of Westphalia, while other territories are granted to his ally, Otto I the Redhead, Duke of Bavaria.
September 18 – King Louis VII dies in Paris after a 43-year reign. He is succeeded by his 15-year-old son, Philip II, who becomes sole ruler of France and reigns until 1223.
Portuguese admiral defeats the Almohad fleet for the second time in two years.
The assembly traditionally considered the first Sejm of the Kingdom of Poland is convened at Łęczyca.

The town of Portsmouth is founded by the Norman merchant Jean de Gisors, who establishes it as a strategic port to facilitate trade between England and France.

Summer – King Baldwin IV sends envoys to Saladin proposing a peace treaty. Due to a severe drought, much of Syria is afflicted by famine, prompting Saladin to agree to a two-year truce. Although Raymond of Tripoli initially denounces the agreement, he is forced to accept it following an Ayyubid naval raid on the port city of Tartus.
Saladin intervenes in a conflict between the Zengids of Mosul and the Artuqids. He persuades the Seljuk sultanate of Rum not to become involved and proceeds to raid Cilician Armenia.
Baldwin IV arranges the marriage of his sister, Sibylla, to Guy of Lusignan, brother of the constable Amalric of Lusignan. Baldwin grants Guy the County of Jaffa and Ascalon as a fief.

March 18 – Emperor Takakura is forced to abdicate by Taira no Kiyomori after a 12-year reign. He is succeeded by his two-year-old son, Emperor Antoku, who will reign until 1185. Kiyomori assumes control of the government, ruling as regent in the child emperor's name.
Genpei War: Prince Mochihito launches a rebellion against the ruling Taira clan. In support of the uprising, Minamoto no Yorimasa issues a call to arms, appealing to several Buddhist monasteries—such as Enryaku-ji, Mii-dera, and others—that have been alienated by Kiyomori.
June 20 – Battle of Uji: Prince Mochihito and Minamoto no Yorimasa take refuge in the Byōdō-in Temple. They appeal to warrior monks for assistance, but are ultimately defeated by Taira forces. Yorimasa commits suicide, and Mochihito is killed while fleeing.
September 14 – Battle of Ishibashiyama: A Taira force of approximately 3,000 men, led by Ōba Kagechika, defeats Minamoto no Yoritomo near Mount Fuji. Yoritomo narrowly escapes by sea and flees to Awa Province.
November 9 – Battle of Fujigawa: Minamoto forces, numbering around 30,000 and commanded by Minamoto no Yoritomo, defeat a Taira army under Taira no Koremori near the Fuji River. The Taira forces retreat in disorder, though Koremori manages to escape.

Alexander Neckam becomes a lecturer in Paris and begins writing De Natura Rerum, one of the earliest Western European works to mention chess.