Grimbald was born around 825 A.D. in Therouanne (Pas-de-Calais), France. He became a Benedictine monk around the year 840 and was ordained a priest in 870. Following his ordination, Grimbald was appointed abbot of Saint-Bertin.
Grimbald's first encounter with King Alfred (of England) came while on his way to Rome in 886. Alfred was so impressed with Grimbald that, a year later, he invited him to come to England. Grimbald accepted. He would reside in a small monastery in Winchester while serving as court scholar.
Grimbald went on to help found the University of Oxford where he served as its first professor of divinity. Alfred even offered Grimbald the prestigious Archbishopric of Canterbury but Grimbald declined, preferring the position of dean of the secular canons of New Minster at Winchester, the town Church.
In his final days, the fast deteriorating Grimbald prostrated himself on the floor in order to receive Holy Communion. He then requested that he be left alone with God for three days. On the fourth day the monks were called to his chamber where he passed away peacefully amidst their prayers.