Guillaume I the Great, the Rash Ivrea de Bourgogne, Count of Burgundy, Count of Macon, was born 1020 to Renaud I de Bourgogne (c990-1057) and Adelaide of Normandy (1002-1038) and died 12 November 1087 Besancon of unspecified causes. He married Etiennette (-aft1087) . Charlemagne (747-814), Rollo of Normandy (860-932), Charlemagne (747-814)/s.
There are several hypotheses about the identity of his wife. She may be a daughter of Berengar Raymond I de Barcelona (1005-1035) by either his first of second wife or Berenger's niece by an unknown brother, a daughter of Adalbert de Lorraine (c1000-1048), or a daughter of Bernard II de Foix (c1014-1077).