He is married to Mathilde Nn.
They got married
Child(ren):
RATPOTO [IV] (-killed in battle Hohenmölsen 15 Oct 1080). The primary source which confirms his parentage has not yet been identified. Vogt von St Emmeram. Graf von Cham. “De Comitibus Ratpotho et filii Udalricus et Ratpotho, Willihalm filius Ger ---“ witnessed the charter dated 17 Jul 1072 under which “--- patriarcha [aquiligiensis Syrus]” confirmed property to Michaelbeuren church after three lives “suam, suæque matris Pilihildæ comitisse nec non Mathildis uxoris fratris sui Friderici”[1160].
m firstly (before 1065) MATHILDE, daughter of ---. The primary source which confirms her marriage has not yet been identified. The origin of Mathilde is not known. Wegener says that she was Mathilde von Lambach, daughter of Arnold [II] Graf von Lambach & his wife Reginlinde ---, but gives no basis for this speculation.
m secondly ---. According to Wegener[1161], Graf Ratpoto's second wife was --- von Kastl, daughter of Hermann [I] Graf von Kastl & his wife Haziga von Diessen, but he appears to base this only on the transmission of the name Hermann to the couple's son, for which there must be other explanations (assuming that this son was Graf Ratpoto's son by his second marriage which, as mentioned below, has not yet been confirmed in the primary sources so far consulted).
Graf Ratpoto [IV] & his first wife had three children:
ULRICH (-Regensburg 24 Feb 1099)
RATPOTO [V] (-Regensburg 14 Apr 1099).
MATHILDE (-[1125]).
Graf Ratpoto [IV] & his second wife had one child:
HERMANN (-18 Mar 1133).
Bronnen:
[1160] Hormayr (1822) Sämmtliche Werke, Band III, p. 38.
[1161] Wegener (1965/67), p. 184.
https://fmg.ac/Projects/MedLands/BAVARIAN%20NOBILITY.htm#RatpotoIVChamdied1080