Saint-Gildas is a Breton saint, believed to have lived during the 6th century. He is known for founding the monastery of Saint-Gildas-de-Rhuys in Brittany, France. His life is often associated with the spread of Christianity in the region and the establishment of monastic communities. Saint-Gildas is celebrated for his piety and dedication to monastic life. He is often depicted in religious art, and his feast day is observed on January 29. His influence is recognized in various churches and places named after him, reflecting his importance in Breton history and culture.