798

Year 798 was a common year starting on Monday of the Julian calendar, the 798th year of the Common Era and Anno Domini designations, the 798th year of the 1st millennium, the 98th year of the 8th century, and the 9th year of the 790s decade. The denomination 798 for this year has been used since the early medieval period, when the Anno Domini calendar era became the prevalent method in Europe for naming years.

Events

Battle of Bornhöved: King Charlemagne forms an alliance with the Obodrites. Together with Prince Drożko, he defeats the Nordalbian Saxons near the village of Bornhöved, obliging these 'northerners' to submit and give hostages against their future good behavior. In the coming years they are granted areas of present-day Hamburg.
King Charles the Younger, a son of Charlemagne, conquers Corsica and Sardinia.
Britain
King Coenwulf of Mercia invades Gwynedd, and kills his rival Caradog ap Meirion during the fighting in Snowdonia. Kings Cynan and Hywel retake the throne. Coenwulf also defeats and captures King Eadberht Præn of Kent. He is blinded and his hands are cut off. He introduces his brother Cuthred as a sub-king of Kent.
Battle of Billington: King Eardwulf of Northumbria defeats the nobleman Wada in battle, who has killed former King Æthelred I.
King Sigeric I of Essex abdicates and departs for a pilgrimage to Rome. He is succeeded by his son Sigered.
Iberia
King Alfonso II of Asturias campaigns against the Arab Muslims in Al-Andalus. With Frankish military support, he raids into Andalusia and sacks Lisbon.
Bahlul ibn Marzuq, a Vascon-Muslim military leader, revolts in Zaragoza against the Arab-Muslim government of Al-Andalus.
By topic

Alcuin, Anglo-Saxon monk and scholar, writes to his friend, the exiled king Osbald of Northumbria, in order to dissuade him.
Theodulf, Frankish poet, is appointed bishop of Orléans. He becomes one of Charlemagne's favoured theologians.