The daughter of a nobleman of Douai, France, Gertrude married the nobleman Rigomer. Widowed at an early age, she devoted herself to the education of her three sons, one of whom was to be venerated as a saint and martyr, Adalbald. Gertrude's son Sigebert was to marry a future saint, Bertha. Following the settlement of her sons, Gertrude withdrew from the world to live at an oratory in Hamage, where she devoted herself to religious exercises and acts of charity. Here she was joined in her life of piety by her granddaughter Eusebia. Gertrude bravely endured the sorrow of learning that her son Adalbald had been assassinated. Adalbald's widow, Rictrude, became a saint. At Hamage Gertrude founded and became abbess of a convent, where she trained her granddaughter for religious life before dying and leaving the government of the convent to her.
