As a result of his diplomacy, the emperor transferred the authority of the abbey from Henry I, Duke of Lower Lorraine, to Arnold.
[citation needed] Arnold forced Henry and his ally Godfrey of Bouillon, to withdraw from the monastery.
Sources disagree on their number of children, but they are believed to include: Another son, Gerard, did not exist.
He appears in older books such as the oldest edition of Belgian National Biographies, based upon a charter of 1101.
Baerten (1969 p. 40 footnote 2) describes this as a mistake caused by modern edition with a wrongly placed comma, and gives references to the literature.