846

By place

Byzantine Empire

• Byzantine–Bulgarian War: The Bulgarians violate the peace treaty, and invade Macedonia along the River Struma. The cities of Serres and Philippi are devastated.

  Europe

• Summer - Breton forces under Nominoe occupy the Frankish cities of Nantes and Rennes. He makes raids in Anjou and threatens Bayeux. King Charles the Bald recognizes him as duke of Brittany.
• Prince Pribina becomes a vassal of the Frankish Empire. King Louis the German grants him land near Lake Balaton. He establishes Blatnohrad, capital of Balaton Principality.
• Frankish forces led by Louis the German invade Moravia. They encounter little resistance, and depose King Mojmir I from the throne. His relative, Rastislav, is set up as the new client ruler.
• The Mozarabs, Iberian Christians who live under Moorish rule, try to repopulate León in Al-Andalus. The city is recaptured by the Muslim Arabs.

  Britain

• King Æthelred II of Northumbria sends military assistance to the Picts, in their fight against the invading Scots.

  Ireland

• Máel Sechnaill mac Máele Ruanaid becomes the first High King of Ireland.

  Arabian Empire

• A Saracen Arab expeditionary force from Africa, consisting of 11,000 men and 500 horses, raid the outskirts of Rome, sacking the basilicas of Old St. Peter's and St. Paul's Outside the Walls.

  Asia

• April 22 - Emperor Wu Zong dies after a 6-year reign. He is succeeded by his uncle Xuān Zong, as Chinese ruler of the Tang Dynasty.
• Jang Bogo, a powerful maritime hegemon of Silla, is assassinated by aristocratic elements at his garrison headquarters by Yeom Jang.