Europe

• Prague Castle
  Prague Castle
  Prague Castle is a castle in Prague where the Kings of Bohemia, Holy Roman Emperors and presidents of Czechoslovakia and the Czech Republic have had their offices. The Czech Crown Jewels are kept here...
  
   is founded.
• The Great Summer Army invades England led by Bagsecg
  Bagsecg
  Bagsecg was a Viking leader referred to as a 'King' and was possibly a King of Denmark, after Horik II died and ruled Denmark after his death from the 860s to his death in 871...
  
   and conquers East Anglia
  East Anglia
  East Anglia is a traditional name for a region of eastern England, named after an ancient Anglo-Saxon kingdom, the Kingdom of the East Angles. The Angles took their name from their homeland Angeln, in northern Germany. East Anglia initially consisted of Norfolk and Suffolk, but upon the marriage of...
  
  ; the buildings destroyed by the Danish invaders include the abbey of Ely
  Ely, Cambridgeshire
  Ely is a cathedral city in Cambridgeshire, England, 14 miles north-northeast of Cambridge and about by road from London. It is built on a Lower Greensand island, which at a maximum elevation of is the highest land in the Fens...
  
   and the monastery of Peterborough
  Peterborough
  Peterborough is a cathedral city and unitary authority area in the East of England, with an estimated population of in June 2007. For ceremonial purposes it is in the county of Cambridgeshire. Situated north of London, the city stands on the River Nene which flows into the North Sea...
  
  .
• August 8 – Treaty of Meerssen
  Treaty of Meerssen
  The Treaty of Meerssen or Mersen was a partition treaty of the Carolingian Empire concluded on 8 August 870 by the two surviving sons of Emperor Louis the Pious, King Charles the Bald of West Francia and Louis the German of East Francia, at Meerssen north of Maastricht, in the present-day...
  
  : Charles the Bald
  Charles the Bald
  Charles the Bald , Holy Roman Emperor and King of West Francia , was the youngest son of the Emperor Louis the Pious by his second wife Judith.-Struggle against his brothers:He was born on 13 June 823 in Frankfurt, when his elder...
  
   and Louis the German
  Louis the German
  Louis the German , also known as Louis II or Louis the Bavarian, was a grandson of Charlemagne and the third son of the succeeding Frankish Emperor Louis the Pious and his first wife, Ermengarde of Hesbaye.He received the appellation 'Germanicus' shortly after his death in recognition of the fact...
  
   divide Lotharingia
  Lotharingia
  Lotharingia was a region in northwest Europe, comprising the Low Countries, the western Rhineland, the lands today on the border between France and Germany, and what is now western Switzerland. It was born of the tripartite division in 855, of the kingdom of Middle Francia, itself formed of the...
  
   among themselves.
• December 31 – The Danes are defeated by a Saxon army at Englefield
  Englefield, Berkshire
  Englefield is a village and civil parish in Berkshire, England. The village is mostly within the bounds of the private walled estate of Englefield House....
  
  , Berkshire
  Berkshire
  Berkshire is a historic county in the South of England. It is also often referred to as the Royal County of Berkshire because of the presence of the royal residence of Windsor Castle in the county; this usage, which dates to the 19th century at least, was recognised by the Queen in 1957, and...
  
  . It is the first of a series of battles between Wessex and the Danes.
• Malta
  Malta
  Malta , officially known as the Republic of Malta , is a Southern European country consisting of an archipelago situated in the centre of the Mediterranean, south of Sicily, east of Tunisia and north of Libya, with Gibraltar to the west and Alexandria to the east.Malta covers just over in...
  
   is conquered by Arabs from Sicily
  Sicily
  Sicily is a region of Italy, and is the largest island in the Mediterranean Sea. Along with the surrounding minor islands, it constitutes an autonomous region of Italy, the Regione Autonoma Siciliana Sicily has a rich and unique culture, especially with regard to the arts, music, literature,...
  
  .
• Borivoj becomes duke of Bohemia
  Bohemia
  Bohemia is a historical region in central Europe, occupying the western two-thirds of the traditional Czech Lands. It is located in the contemporary Czech Republic with its capital in Prague...
  
  .
• Charles the Bald
  Charles the Bald
  Charles the Bald , Holy Roman Emperor and King of West Francia , was the youngest son of the Emperor Louis the Pious by his second wife Judith.-Struggle against his brothers:He was born on 13 June 823 in Frankfurt, when his elder...
  
   marries Richilde.

Religion

• Michael II succeeds Michael I as Patriarch of Alexandria
  Patriarch of Alexandria
  The Patriarch of Alexandria is the Archbishop of Alexandria and Cairo, Egypt. Historically, this office has included the designation of Pope , and did so earlier than that of the Bishop of Rome...
  
  .
• The Autonomous Bulgarian Archbishopric is established.
• February 28 – The Fourth Council of Constantinople
  Fourth Council of Constantinople
  The Fourth Council of Constantinople of 879-880 is believed to have been the Eighth Ecumenical Council by some Eastern Orthodox. Photius had been appointed Patriarch of Constantinople but deposed by a Council of Constantinople called in 869 by Emperor Basil I the Macedonian and Pope Adrian II...
  
   ends.

Births

• Al-Farabi
  Al-Farabi
  ' known in the West as Alpharabius , was a scientist and philosopher of the Islamic world...
  
  , Persian philosopher and scientist
  Scientist
  A scientist in a broad sense is one engaging in a systematic activity to acquire knowledge. In a more restricted sense, a scientist is an individual who uses the scientific method. The person may be an expert in one or more areas of science. This article focuses on the more restricted use of the word...
  
  
• Zwentibold
  Zwentibold
  Zwentibold was the illegitimate son of the Carolingian Emperor Arnulf of Carinthia. In 895 his father, then king of East Francia, granted him the Kingdom of Lotharingia, which he ruled until his death.After his death he was declared a saint and martyr by the Catholic Church.- Life :Zwentibold...
  
  , King of Lotharingia
  Lotharingia
  Lotharingia was a region in northwest Europe, comprising the Low Countries, the western Rhineland, the lands today on the border between France and Germany, and what is now western Switzerland. It was born of the tripartite division in 855, of the kingdom of Middle Francia, itself formed of the...
  
  

Deaths

• November 20 – King Edmund of East Anglia
• al-Bukhari, Persian hadith compiler
• Al-Kindi
  Al-Kindi
  ' , known as "the Philosopher of the Arabs", was a Muslim Arab philosopher, mathematician, physician, and musician. Al-Kindi was the first of the Muslim peripatetic philosophers, and is unanimously hailed as the "father of Islamic or Arabic philosophy" for his synthesis, adaptation and promotion...
  
  , philosopher