Saint Gildas was a 6th-century monk and writer from Britain, known for his role in the early Christian church. He is often associated with the founding of several monasteries in Brittany, France, and is recognized for his efforts in spreading Christianity in the region. Gildas is also credited with writing "De Excidio et Conquestu Britanniae," a historical work that discusses the fall of Roman Britain and the moral decline of its people. Gildas is venerated as a saint in both the Catholic Church and the Eastern Orthodox Church. His feast day is celebrated on January 29. He is often depicted in art holding a book or a staff, symbolizing his role as a teacher and leader in the early Christian community. His legacy continues to influence the understanding of early medieval history in Britain and Brittany.