• Born: Normandy, France
• Married:
• Died: 1038, Vandreuil, Normandie, France

  Research Notes:

Orderic Vitalis records that "Osbernus Herfasti filius" was "de pago Calcegio oriundus", although in the context of a passage which is anachronistic. "Duke Richard [II]" donated property to the abbey of Mont Saint-Michel by charter dated to [1026], subscribed by "…Osbernus filius Arfast, Ranulfus frater eius". "…Osbe filius Herfasti…" witnessed the charter dated to [1030] under which Robert II Duke of Normandy confirmed rights of Mont Saint-Michel. Steward (dapifer) of Robert II and Guillaume II Dukes of Normandy. "Rotberti comitis, Osberni dapiferi…" witnessed the charter dated to [1030/35] under which "Erchembaldus vicecomes" donated "prata de Salhus et…in Sarlosvilla jure hereditario" to the abbey of Sainte-Trinité de Rouen.

An undated charter, recording a donation to Sainte-Trinité de Rouen, records that "Osbernus dapifer" was killed "a suis hostibus". He is named "Osberni cognomento Pacifici" in the charter dated to [1035/60] which records the donation by his widow and two sons to Rouen Sainte-Trinité for his soul. Guillaume of Jumièges records that "Osbernus...procurator principalis domus, Herfasti Gunnoris comitissæ fratris filius" was killed while sleeping "in cubiculo ducis cum ipso in valle Rodoili" by "Willelmo Rogerii de Montegumeri filio", dated to early in the reign of Duke Guillaume II from the context.

Murdered. ²