859

By place

Europe

• January 15 - Battle of St. Quentin: Frankish forces, led by Humfrid, defeat King Louis the German at Saint-Quentin. Humfrid is enfeoffed with the County of Autun, and appointed Margrave of Burgundy, by King Charles the Bald.
• Summer - The Viking chieftains Hastein and Björn Ironside begin an expedition, and sail from the Loire River with a fleet of 62 ships, to raid cities and monasteries in the Mediterranean Sea.
• Viking raiders invade the Kingdom of Pamplona, and capture King García Íñiguez I, somewhere in the Andalusian heartland. They extort a ransom, rising to around 70,000 gold dinars.
• The Russian city of Novgorod is first mentioned in the Sofia Chronicles.
• Winter - The weather is so severe that the Adriatic Sea freezes, and Italy is covered in snow for 100 days.

  Iberian Peninsula

• Battle of Albelda: King Ordoño I of Asturias, and his ally García Íñiguez I, defeat the Muslims under Musa ibn Musa al-Qasawi at Albelda.
• Viking raiders burn the mosques of Seville and Algeciras in al-Andalus.

  Africa

• The University of Al Karaouine is founded in Fes, by Fatima al-Fihri.

  China

• September 7 - Emperor Xuān Zong dies after a 13-year reign. He is succeeded by his eldest son Yi Zong, as ruler of the Tang Dynasty.