Europe

• Louis the Pious
  Louis the Pious
  Louis the Pious , also called the Fair, and the Debonaire, was the King of Aquitaine from 781. He was also King of the Franks and co-Emperor with his father, Charlemagne, from 813...
  
   attempts to divide his empire among his sons.
• Ethelwulf
  Ethelwulf of Wessex
  Æthelwulf, also spelled Aethelwulf or Ethelwulf; Old English: Æþelwulf, meaning 'Noble Wolf', was King of Wessex from 839 until his death in 858. He is the only son who can indisputably be accredited to King Egbert of Wessex. He conquered the kingdom of Kent on behalf of his father in 825, and was...
  
   succeeds Egbert
  Egbert of Wessex
  Egbert was King of Wessex from 802 until his death in 839. His father was Ealhmund of Kent...
  
   as king of Wessex
  Wessex
  The Kingdom of Wessex or Kingdom of the West Saxons was an Anglo-Saxon kingdom of the West Saxons, in South West England, from the 6th century, until the emergence of a united English state in the 10th century, under the Wessex dynasty. It was to be an earldom after Canute the Great's conquest...
  
  .
• Uen
  Uen of the Picts
  Uuen [Wen] or Eogán in Gaelic was king of the Picts, or of Fortriu , in what is now Scotland....
  
   is succeeded by Uurad
  Uurad of the Picts
  Uurad or Ferat son of Bargoit was king of the Picts, perhaps from 839 onwards.No two versions of the king-lists known as the Pictish Chronicle give exactly the same version of his name...
  
   as king of the Picts
  Picts
  The Picts were a group of Late Iron Age and Early Mediaeval people living in what is now eastern and northern Scotland. There is an association with the distribution of brochs, place names beginning 'Pit-', for instance Pitlochry, and Pictish stones. They are recorded from before the Roman conquest...
  
  .
• The reign of Alpin II of Dalriada begins (approximate date).
• The Balaton principality
  Balaton Principality
  The Principality of Lower Pannonia was a Slavic principality located in the western part of the Pannonian plain, between the rivers Danube to its east The Principality of Lower Pannonia (also called Pannonia, Lower Pannonia, Pannonian Principality, Transdanubian Principality, Slavic Pannonian...
  
   is created.
• The Saracen
  Saracen
  Saracen was a term used by the ancient Romans to refer to a people who lived in desert areas in and around the Roman province of Arabia, and who were distinguished from Arabs. In Europe during the Middle Ages the term was expanded to include Arabs, and then all who professed the religion of Islam...
  
   troops established in the South pillage Ancona
  Ancona
  Ancona is a city and a seaport in the Marche region, in central Italy, with a population of 101,909 . Ancona is the capital of the province of Ancona and of the region....
  
   in Central Italy
  Central Italy
  Central Italy is one of the five official statistical regions of Italy used by the National Institute of Statistics , a first level NUTS region and a European Parliament constituency...
  
  .

Deaths

• King Aznar I Galíndez
  Aznar I Galíndez
  Aznar Galíndez I was the Count of Aragon and Conflent from 809 and Cerdanya and Urgell from 820. Aznar has been confused with Aznar Sánchez, Duke of Gascony, and some authorities have even considered the two like-named contemporaries to be one and the same person.Aznar succeeded Aureolus as count...
  
   of Aragon
• Egbert of Wessex
  Egbert of Wessex
  Egbert was King of Wessex from 802 until his death in 839. His father was Ealhmund of Kent...
  
  
• Wiglaf
  Wiglaf of Mercia
  Wiglaf was King of Mercia from 827 to 829 and again from 830 until his death. His ancestry is uncertain: the 820s were a period of dynastic conflict within Mercia and the genealogy of several of the kings of this time is unknown...
  
  , King of Mercia
  Mercia
  Mercia was one of the kingdoms of the Anglo-Saxon Heptarchy. It was centred on the valley of the River Trent and its tributaries in the region now known as the English Midlands...