[HILDEGARD ([1030]-). This speculative affiliation is suggested by Jackman[210] who emphasises that it could provide an explanation based on heredity for the appointment of Hildegard's son, Friedrich von Büren, as Duke of Swabia in 1079. This assumes the need for such a hereditary basis, whereas it appears that the duchy of Swabia was awarded on the basis of the political or economic power of the nominee. In addition, if heredity had been the basis for the nomination, there would clearly have been other candidates with a senior claim. Decker-Hauff[211] suggests that Hildegard, wife of Friedrich von Büren, was the daughter of Louis de Mousson, but Jackman says that this should be rejected on chronological grounds given the birth of Sophie de Lotharingia, wife of Louis de Mousson, in [1020] which means that she could not have been the grandmother of Friedrich I Duke of Swabia who was born in [1050]. The wife of Friedrich von Büren is not named in Europäische Stammtafeln[212]. m ([1047]) FRIEDRICH von Büren, son of FRIEDRICH Pfalzgraf von Schwaben & his wife --- (-[1068]).]