Gildas the Historian was a 6th-century British monk and writer, known for his work "De Excidio et Conquestu Britanniae." This text provides a valuable account of the history of Britain during the post-Roman period, detailing the decline of Roman influence and the subsequent invasions by the Saxons. Gildas is often regarded as one of the earliest historians of Britain. His writings not only offer insights into the political and social conditions of his time but also reflect his Christian beliefs and moral concerns. His work remains a crucial source for understanding early medieval Britain and its challenges.