All the near contemporary primary sources so far consulted name Rudolf, father of Heinrich and Welf [II] as the brother of Konrad Bishop of Konstanz. For example, Berthold's Chronicon of Zwiefalten names "Couniza, Welphonis primi nostri advocati mater, filia…Welphonis Carentorum ducis qui fuit Roudolfi fratris sancti Counradi filius". If this is correct, Ita von Öhningen would have been at least 40 years younger than her husband. As this seems unlikely, the most probable explanation is that there has been a conflation of two individuals, father and son, both named Rudolf but there is no proof that this is correct.
The Historia Welforum records that "Roudolfus" was buried "in Altorfensi cenobio iuxta patrem et matrem". The necrology of Weingarten records the death "VI Id Mar" of "Ruodolfus com frater sancti Chuonradi…et Welf filius eius…hic sepulti". 1
Research Notes: