867 CE

Treaty of Compiègne: King Charles the Bald cedes the Cotentin Peninsula to Salomon, duke ('king') of Brittany, after he had sent his son-in-law Pascweten to negotiate a peace. Charles orders the fortification of the cities of Tours, Le Mans and Compiègne. Emperor Michael III is murdered, by order of his co-emperor Basil I. Basil becomes sole ruler (basileus) of the Byzantine Empire, and founds the Macedonian Dynasty (until 1056). Basil rebuilds the Byzantine army and navy, in an effort to restore the empire. Photius I ("the Great"), patriarch of Constantinople, is removed from office and banished. Ignatius is reinstated as patriarch by Basil I.

In the 860s, the 9th century.

Geopolitics & Diplomacy

  • August – Treaty of Compiègne: King Charles the Bald cedes the Cotentin Peninsula to Salomon, duke ('king') of Brittany, after he had sent his son-in-law Pascweten to negotiate a peace. Charles orders the fortification of the cities of Tours, Le Mans and Compiègne.source
  • Bořivoj I declares himself duke (knyaz) of Bohemia, and founds the Přemyslid Dynasty (approximate date).source

Conflict & Security

  • Deira, the southernmost part of Northumbria, is conquered by the Vikings. Ivar the Boneless, one of their leaders, installs a puppet king of Northumbria, Ecgberht I.source
  • The rival monarchs of Northumbria, Ælla and Osberht, join forces in an attempt to expel the Great Heathen Army, but are defeated in battle by Ivar the Boneless and Halfdan Ragnarsson. Osberht is killed in battle, while Ælla is reportedly captured, before being subject to the blood eagle: a combined method of torture and execution.source

Exploration & Expansion

  • Vikings or "Danes" (the two terms were often used interchangeably at the time), comprising the Great Heathen Army, advance northward from bases in the Kingdom of East Anglia, into the Anglo-Saxon Kingdom of Northumbria.source
  • Surviving members of the Northumbrian royal court flee into the northernmost part of the kingdom, Bernicia.source

Religion & Belief

  • September – Photius I ("the Great"), patriarch of Constantinople, is removed from office and banished. Ignatius is reinstated as patriarch by Basil I.source
  • The Council of Constantinople is held (presided over by Patriarch Photius), which anathematizes the use of the Filioque clause in the Creed, and also Pope Nicholas I, for his attacks on the work of Greek missionaries in Bulgaria.source

Births

  • October 10 – Li Siyuan, emperor of Later Tang (died 933)source
  • Stephen I, patriarch of Constantinople (died 893)source
  • Kyŏn Hwŏn, king of Later Baekje (Korea) (died 936)source
  • Pribislav, prince (knyaz) of Serbia (approximate date)source
  • Zhu Jin, Chinese warlord (died 918)source
  • Zhao Zong, emperor of the Tang Dynasty (died 904)source

Deaths

  • March 21 – Osberht, king of Northumbriasource
  • March 21 – Ælla, king of Northumbriasource
  • September 24 – Emperor Michael III is murdered, by order of his co-emperor Basil I. Basil becomes sole ruler (basileus) of the Byzantine Empire, and founds the Macedonian Dynasty (until 1056). Basil rebuilds the Byzantine army and navy, in an effort to restore the empire.source
  • November 13 – Nicholas I, pope of the Catholic Churchsource
  • November 13 – Pope Nicholas I dies after a 9-year reign. He is succeeded by Adrian II (also referred to as Hadrian II), as the 106th pope of Rome.source
  • Lazarus Zographos, Byzantine monk and paintersource
  • Muhammad ibn Abdallah, Abbasid governorsource
  • Fujiwara no Yoshisuke, Japanese statesman (born 813)source
  • Fujiwara no Yoshimi, Japanese nobleman (born 813)source
  • Qarin I, ruler (spahbed) of the Bavand Dynastysource
  • Auisle, Viking leader (approximate date)source
  • Michael III, emperor of the Byzantine Empire (born 840)source
  • Wasif al-Turki, Abbasid generalsource
  • Gottschalk of Orbais, German monk and theologiansource