Born to the Belgian nobility; son of Stance and Plectrude. Raised in a military atmosphere. Courtier to the Count of Namur. Disappointed by court life, and ashamed of the many privileges he received from his family and military post, Gerard realized that he was called to the monastic life.

He found Belgian monasteries to lax in their discipline. While visiting Frace in 917 on a mission from the Couny, Gerard decided the life of the monks of Saint Denis was right for him. He settled his worldly affairs, and took vows at the monastery. There Gerard became an example to other monks in following the Rule, and in his devotion to prayer. His life, and his encouragement of the brothers, helped Saint Denis becoming an example for monasteries throughout Europe.

He was ordained, but wrestled with feelings of inadequacy as a priest. After 11 years, the abbot asked Gerard to return home to form a monasteries there. Abbot of the new monasteries, he soon gained renown for his strict observance of the Benedictine Rule This led many religious and political leaders to request that he reform monasteries throughout Flanders, Lorraine, and hampagne. Near the end of his life Gerard returned to the  monastery he built, and spent the rest of his life there in solitude and prayer.