Gertrude of Flanders, Duchess of Lorraine

Gertrude married firstly Henry III, Count of Leuven (died wounded in a tournament in Tournai in 1095), of the House of Reginar. He was count of Louvain from 1078 to 1095 and landgrave of Brabant from 1085. At Henry's death, his brother Godfrey I succeeded as count and landgrave. From 1106 he also became duke of Lower Lorraine.

They had four children, probably all daughters (born about 1092-1096), assumingly including:

• Adelaide (d. 1158), wife of duke Simon I of Lorraine (1076 – 1138), son of her stepfather Theodoric with Hedwige (d. c. 1090).
• Gertrude, wife to Lambert, count of Montaigu and Clermont

Secondly in 1096 she married Theodoric II, Duke of Lorraine "Thierry" (d. 1115), son of Gérard of Alsace, Count of Metz, Duke of Lorraine (-1070), of the House of Lorraine-Alsace. Thierry was a widower with a son Simon, and a daughter Gertrude. They had the following issue:

• Thierry of Alsace "Theodoric" (c. 1099 – 1168), lord of Bitche, also Count of Flanders from 1128. Married to Sibylla of Anjou, and father to Margaret I, Countess of Flanders and Matthew, Count of Boulogne
• Henry I (d. 1165), bishop of Toul
• Ida, married Sigefroy (d. 1104), count of Burghausen
• Ermengarde, married Bernard III Gros de Brancion (fr)
• Gisela, married Frederick, count of Saarbrücken