Together with his eldest brother Richard FitzGilbert, in 1066 Baldwin participated in the Norman Conquest of England.
[4] He is listed in the Domesday Book as "Baldvinus Vicecomes", literally translated as "Baldwin the Viscount", a Norman title signifying that he had an administrative responsibility over the county of Devon, which office had become almost synonymous with the Sheriff of Devon, an Anglo-Saxon office.
His first wife was named Albreda, whom Orderic Vitalis refers to as a daughter of the aunt of William the Conqueror, presumably niece of his mother Herleva.
[6] He had three sons who all died childless, and two daughters:[6] Baldwin also had an illegitimate child, Wiger, a monk at Bec.
[7] Following the deaths of his three sons without heirs, his daughter Adeliza was his ultimate sole heiress.