Richarius was a 7th-century Frankish monk and priest who lived in the region of Ponthieu. Originally a pagan, he converted to Christianity after providing hospitality to two Welsh missionaries. Following his conversion, he led an ascetic life, practiced rigorous fasting, and traveled to England to preach and heal the sick. He is primarily remembered for establishing two monasteries, including the one at Centule, which eventually became the site of the town now known as Saint-Riquier.