Geremarus was a 7th-century Frankish monk and abbot who served as a counselor to Merovingian kings, including Dagobert I and Clovis II. Born in the Beauvais region, he initially lived as a layman, during which time he established the Isle-sur-Epte Abbey. Following his ordination, he led the Pental Abbey as superior, though he eventually withdrew to live as a hermit after facing opposition from his monks. He later founded the monastery at Fly, which became known as Saint-Germer-de-Fly, where he served as abbot until his death in 658.