Ambrosius Aurelianus as a war leader of the Romano-British who won an important battle in the 5th century, according to a 6th-century British monk best known for his scathing religious polemic which recounts the history of the Britons before and during what? 
Gildas: Gildas (Breton: "Gweltaz", c. 500–570) — also known as Gildas the Wise or Gildas Sapiens — was a 6th-century British monk best known for his scathing religious polemic "De Excidio et Conquestu Britanniae", which recounts the history of the Britons before and during the coming of the Saxons.
i don't know