Saint Hadelin was a 7th-century monk of noble birth who played a significant role in spreading Christianity within the region of modern-day Belgium. Originally from Guyenne, he served at the court of Sigebert of Austrasia before dedicating himself to monastic life. Studying under Remaclus at several abbeys, he later accompanied his mentor to Maastricht. He is primarily recognized for his missionary efforts and for establishing monastic communities, including the monastery at Celles and another at Visé, before retiring to a life as a hermit.