Baring-Gould’s sources: Belgian Martyrologies, and in Saussaye's supplement to the Gallican Martyrology. Authorities:—Mention of him in the life of his wife S. Richtrudis, by Hucbald the monk, a.d. 907; and in the life of his daughter, S. Eusebia. In some Martyrologies he is styled Martyr, but generally Duke.

Duke Adalbald was a grandson of S. Gertrude of Hamage. His mother's name was Gerberta. From his earliest youth he was a model of virtue, even in the court of the king. He married S. Richtrudis, by whom he had S. Maurontus, his eldest son, who became afterwards abbot; and three virgin saintly daughters, Clotsendis, Eusebia, and Andalsendis. S. Amandus baptized Clotsendis, and Queen Nanthild, wife of King Dagobert, was sponsor to Eusebia. On his way to Gascony for some purpose, he was waylaid and murdered, by certain persons who were displeased at his marriage with Richtrudis. It seems probable, therefore, that the crime was committed on account of some property, but nothing for certain is known of the motive actuating the murderers. Relics at S. Amand, in Flanders.