Brennius

Brennius was a legendary king of Northumberland and Allobroges, as recounted by Geoffrey of Monmouth. He was the son of Dunvallo Molmutius and brother of Belinus, probably based upon one or both of the historical Brenni.

Claimant to the throne of Britain

In an effort to win the crown of Britain, Brennius and Balinus waged war between each other to determine who should succeed their father. Many battles were fought between the two brothers until a time came when their friends intervened and a compromise was decided upon. Belinus became the King of the Britons with Brennius as King of Northumberland.

Five years later, Brennius wed the daughter of the King of Norway without consulting Belinus. Belinus invaded Northumberland and seized Brennius's land. Brennius heard of this violation and gathered a large Norwegian army together to sail for Britain. On the way, a fleet of ships under the King of Denmark attacked because the king wanted Brennius's wife for himself. They fought in the open ocean and the two sides dispersed. The King of Denmark managed to capture the wife of Brennius but he then got lost and landed on Britain. Belinus captured the king and his brother's wife. Brennius landed in Albany and demanded the return of all his lands and his wife. If not, he swore he would kill Belinus if they ever met in battle.