De Excidio et Conquestu Britanniae
“On the Ruin and Conquest of Britain”
The War of the Twelve Kings is an event described in the work of the British historian Gildas.
Gildas was a sixth-century monk and historian who wrote a Latin literary work around the late fifth and early sixth centuries, commonly referred to as De Excidio et Conquestu Britanniae. His work provides one of the earliest historical accounts of post-Roman Britain and includes a section known as the War of the Twelve Kings.
According to Gildas, after the Romans left Britain, the island fell into a state of disarray and was plagued by internal conflicts and invasions from various groups. During this time, local British leaders vied for power, leading to the War of the Twelve Kings.
Gildas mentions a leader named Ambrosius Aurelianus (also known as Ambrosius Aurelius) as one of the protagonists in the war. Ambrosius is described as a Roman-British leader who rose to prominence during the tumultuous post-Roman period. Ambrosius Aurelianus is portrayed as a skilled military leader who fought against the various British kings and their allies during the war. He is credited with some military successes in defending the Britons against external threats.
The details of the outcome of the war are not fully described by Gildas. However, he does mention that Ambrosius, with the help of God, achieved some victories against the invading forces, providing a brief respite for the Britons.
The War of the Twelve Kings is mentioned briefly in Gildas’ work, and the names of the twelve kings involved are not specifically listed. The details about the war, the names of the kings, and the events surrounding it are relatively scarce in Gildas’ writing. The De Excidio et Conquestu Britanniae focuses more on the moral and religious aspects of the histroical events it describes, rather than providing a comprehensive account of the military conflicts themselves. Gildas emphasizes the sins and shortcomings of the British rulers and population as the primary reasons for the calamities befalling the island, including the war.
Later Arthurian connections
Ambrosius Aurelianus is considered one of the possible historical figures upon whom the legendary King Arthur might have been based. Over time, as the Arthurian legends developed, elements of Ambrosius’ story and character may have influenced the portrayal of King Arthur in later medieval romances.
Source
De Excidio et Conquestu Britanniae | Gildas, c. 540