AD 926: Battle of the Bosnian Highlands: Bulgarian forces under Duke Alogobotur are ambushed and defeated by a Croatian army of King Tomislav, in the mountainous area of Eastern Bosnia.
AD 921: On 7 November, the Treaty of Bonn was signed between Charles III of France and Henry I of Germany in a minimalist ceremony aboard a ship in the middle of the Rhine not far from Bonn, recognizing the border between their two Frankish kingdoms.
AD 849: The Battle of Ostia, a naval battle between an Italian league of Papal, Neapolitan, Amalfitan, and Gaetan ships and a Muslim fleet, ended in an Italian victory, bringing an end to the period of Muslim military incursions in Rome.
AD 846: The Arab raid against Rome took place, with plundering taking place in the outskirts of the city, but the city proper being protected by the Aurelian Walls.
AD 843: The Treaty of Verdun was signed, ending the Carolingian civil war and dividing the Carolingian Empire between Lothair I, Louis II and Charles II, the surviving sons of the emperor Louis I.
AD 829: Emperor Michael II dies after an 8-year reign in Constantinople, and is succeeded by his 16-year-old son Theophilos, as sole emperor of the Byzantine Empire.