From "The Mortimer Family of Wigmore: An outline lineage" by Ian Mortimer, Version 3.0, 16 June 2016 < PDF > Page 46-47

Jean de Mortemer, seigneur of Couhé, who married first Philippe de la Rochfoucauld, dame de Roissac, and secondly Rosine de Pêrusse, by whom he had at least two children.

1. Guy de Mortimer (d. 1512), seigneur d’Ozillac et Roissac, who married Françoise Bouchard d’Aubeterre, dame d’Ozillac, by whom he had issue:

2. Charles de Mortemer, 2nd son, (fl. 1560), who was the last member in the male line.

References

1. "The Mortimer Family of Wigmore: An outline lineage" by Ian Mortimer, Version 3.0, 16 June 2016 < PDF > Page 46.
2. Watson, G.W. "Geoffrey de Mortemer and his Descendants", in Selby, Walford D. (ed. v. 1-5); Keith W. (ed. v. 6-10) Murray; and H.W. Forsyth (ed. v. 11-38) Harwood. The Genealogist (New Series). (London: George Bell & Sons) p. 1-16. < Archive.Org >
3. https://www.werelate.org/wiki/Person:Jean_de_Mortemer_%282%29
4. https://www.genealogics.org/getperson.php?personID=I00693392&tree=LEO cites
   1. Talbot, Mike, Ancestor List of Marie Julie de St.Maure extracted from Pere Anselme and Chesnaye Desbois. 38