This great missionary was born in lower Poitou about the year 584. At the age of twenty, he retired to a small monastery in the island of Yeu, near that of Re. He had not been there more than a year when his father discovered him and tried to persuade him to return home. When he threatened to disinherit him, the saint cheerfully replied, "Christ is my only inheritance." Amand afterward went to Tours, where he was ordained, and then to Bourges, where he lived fifteen years under the direction of St. Austregisilus, the bishop, in a cell near the cathedral. After a pilgrimage to Rome, he returned to France and was consecrated bishop in 629 without any fixed See, receiving a general commission to teach the Faith to the heathens. He preached the gospel in Flanders and northern France, with a brief excursion to the Slavs in Carinthia and perhaps, to Gascony. He reproved King Dagobert I for his crimes and accordingly, was banished. But Dagobert soon recalled him, and asked him to baptize his newborn son Sigebert, afterwards to become a king and a saint. The people about Ghent were so ferociously hostile that no preacher dared venture among them. This moved Amand to attempt that mission, in the course of which he was sometimes beaten and thrown into the river. He persevered, however, and in the end people came in crowds droves to be baptized.

As well as being a great missionary, St. Amand was a father of monasticism in ancient Belgium, and a score of monasteries claimed him as founder. He found houses at Elnone (Saint-Amand-les-Eaux), near Tournai, which became his headquarters, St. Peters on Mont-Blendin at Ghent, but probably not St. Bavo's there as well; Nivells, for nuns, with Blessed Ida and St. Gertrude, Barisis-au-Bois, and probably three more. It is said, though possibly apocryphal, that in 646 he was chosen bishop of Maestricht, but that three years later, he resigned that See to St. Remaclus and returned to the missions which he had always had most at heart. He continued his labors among the heathens until a great age, when, broken with infirmities, he retired to Elnone. There he governed as Abbot for four years, spending his time in preparing for the death which came to him at last soon after 676. That St. Amand was one of the most imposing figures of the Merovingian epoch, is disputed by no serious historian; he was not unknown in England, and the pre-Reformation chapel of the Eyston family at east Hendred in Birkshire is dedicated in his honor.