The Genealogica Comitum Flandriæ Bertiniana names (in order) "Balduinum Haanoniensem, et Robdbertum cognomento postea Iherosolimitanum, et Matilde uxorem Guillelmi regis Anglorum" as the children of "Balduinum Insulanum [et] Adelam". The Chronicle of Alberic de Trois-Fontaines names (in order) "Balduinum sextum, Robertum cognomento Fresonem, Philippum patrem Guilelmi de Ypra et filias duas Iudith, quam duxit Tostinus comes Nortdanimbronum in Anglia et Mathilda…Normannorum ducissa", which confuses three generations of the family of the counts of Flanders.
Baudouin's father sent him to be educated at the court of Emperor Heinrich III, who installed him as count in the march of Antwerp in , although this was taken away in  after his father opposed the emperor.
He succeeded in 1055 as BAUDOUIN I Comte de Hainaut, by right of his wife. He succeeded his father in 1067 as BAUDOUIN VI Count of Flanders.
The Annales Blandinienses record the death in 1070 of "Baldwinus marchisus, qui Hasnoni sepultus est". The Annales Elnonenses Maiores record Baudouin's death "XVI Kal Aug" and his burial "Hasnonie". 2