The Notitiæ Fundationis Monasterii Bosonis-Villæ names (in order) "Adalbertus, Gerhardus, Cuonradus, Adalbero, Beatrix, Cuono, Huoda abbatissa, Azelinus, Ida, Adeleth" as children of "Gerhardus comes [et] Gisela". In an earlier passage, the same source names "Odelrico comite et Gerhardo duce" as sons and successors of "Gerhardus comes marchio [et] cum uxore sua Gisela".
Comte de Metz, Comte de Châtenois. Emperor Heinrich III appointed him as GERARD Duke of Upper Lotharingia after his brother was killed in battle in Nov 1048. The dating clause of a charter dated 15 Oct 1062, which records a judgment of Udo Bishop of Toul, states “regnante Henrico IV Rom. Rege, Duce Gerardo, Ardulpho Tullensi comite...”. "Gerardus…Lothariensium dux" donated property to Echternach abbey by charter dated 11 Apr 1067 which names "uxoris mea Hadvidis filiique nostre Theoderici…patris mei Gerhardi matrisque meæ Gislæ".
According to the 14th century chronicle of Jean de Bayon, Duke Gérard was poisoned. The Obituaire de Saint-Mansuy records the death "11 Aug" of "Gerardus dux". 2