Robert II of France
Gertrude was daughter of Robert I, Count of Flanders (c. 1035–1093) and Gertrude of Saxony (c. 1030 – 1113). Robert was son of Baldwin V of Flanders and Adèle, a daughter of King Robert II of France, and Gertrude daughter of the Duke of Saxony. She was sister of Robert II, Count of Flanders (c. 1065 – 1111), "Robert the Crusader".