|Covid-19|Battle of Ostia: A Saracen Arab fleet from Sardinia sets sail towards Rome. In response, Pope Leo IV forms a coalition of maritime Italian cities, including Naples, Amalfi and Gaeta, led by Admiral Caesar — which is assembled off the re-fortified port of Ostia — and repels the Saracen marauders. Their navy is scattered, resulting in many sunken vessels. Rome is saved from plunder and the expansion of the Aghlabids.
Frankish forces under King Charles the Bald invade southern France, and conquer the territory of Toulouse. He appoints Fredelo as count (comté) of Toulouse, who founds the Rouergue dynasty. Aquitaine is submitted to the West Frankish Kingdom.
The Armenian prince Bagrat II begins a rebellion against Caliph Al-Mutawakkil, of the Abbasid Caliphate.
In the Chinese capital city of Chang'an, an imperial prince is impeached during the Tang Dynasty from his position by officials at court, for erecting a building that obstructs a street in the northwesternmost ward in South Central Chang'an.
King Pyinbya of Burma founds the city of Pagan, located in the Mandalay Region, and fortifies it with walls.
Alfred the Great, king of Wessex (d. 899)
Isma'il ibn Ahmad, Muslim emir (d. 907)
Ali ibn al-Madini, Muslim scholar (b. 778)
Conaing mac Flainn, king of Brega (Ireland)
Connagan, bishop of Clonfert (Ireland)
Guntbold, archbishop of Rouen
Harthamah ibn al-Nadr, Muslim governor
Itakh al-Khazari, Muslim general
Ragenar, bishop of Amiens
Theophylact, Byzantine co-emperor
Walafrid Strabo, Frankish theological writer
Zhang Zhongwu, Chinese general
Year 849 (DCCCXLIX) was a common year starting on Tuesday (link will display the full calendar) of the Julian calendar.