Simon was a son of Simon III? of Commercy and grandson of Gaucher I :fr:Gaucher Ier de Broyes-Commercy|, Seigneur of Broyes-Commercy, who was succeeded by Simon III's brother Gaucher II in Commercy, while Hugues, the elder brother of Gaucher I, had Broyes :fr:Liste des seigneurs de Broyes| from their mother Agnès of Broyes. It is not clear if Simon III actually was a Seigneur of Commercy, but at least the title came to his descendants. Simon's mother was Mathilde, Countess of Saarbrücken from 1270, daughter of Simon III, Count of Saarbrücken with Lauretta of Upper Lorraine. The County of Saarbrücken was given to the eldest sister Loretta, with the others getting a share, but at her death the title went to Mathilde. As a widow Mathilde remarried in c.1248 to Amadeus :fr:Amédée III de Montfaucon|, Seigneur of Montfaucon and had more children. Simon's sister Laure, married Jean "the old", Count of Chalon, Sire of Salins, regent of the County of Burgundy, and had several children, including Jean I of Châlon-Arlay. Simon married twice and founded the House of Saarbrücken-Commercy :fr:Seigneurie de Commercy|, having both fiefs as inheritance in 1274.
Marriage and issue
In 1265 Simon married Elisabeth of Broyes-Commercy, daughter or granddaughter of his uncle Gaucher II of Broyes-Commercy :fr:Seigneurie de Commercy|, married to Marguerite of Bellevesvre. These had two known children, Jeanne-Agnès and Marguerite who married Richard of Monnet. Simon and his wife had one known child:
, who succeeded as Count of Saarbrücken. Jean also succeeded Simon as Seigneur of Commercy, already in 1297.
*Jean married Mahaut/Mathilde of, daughter of Gobert VII :fr:Maison d'Aspremont| and had possibly the following children:
**Simon, married 1309 Margarethe of Savoy, daughter of Louis I of Vaud. Their son was Johann/Jean II, who succeeded Jean I in 1342, in Saarbrücken and 1326 in the part of Commercy called "Saarbrücken" or "Château bas", and married Ghislette of Bar and had one daughter, Johanna who married John I, Count of Nassau-Weilburg, and had several children. Formally she succeeded briefly as Countess of Saarbrücken, and as regent of Nassau-Weilburg.
**Jeanne, married to Gerhard VII, Herr of Blankenheim :de:Burg Blankenheim|.
**Marguerite, married to Louis III of Cossonay :fr:Famille de Cossonay|, Sire of Bercher, but with no children recorded.
**Mahaut/Mathilde, married Johann III, Lord of Lichtenberg :fr:Seigneurie de Lichtenberg|. Secondly she married 1334 to Simon I, Count of Salm :de:Stammliste des Hauses Salm|.
**Pierre/Peter
**Jean/Johann II of Commercy :fr:Jean II de Sarrebruck-Commercy|, Seigneur of the rest of the estate, "Château haut", Sire of Commercy and Venizy. In 1335 he married Alix,, Dame of Venizy and Brequenay, daughter of Guillaume of Joinville and Béatrice de Brienne, and had about seven children, including Jean III of Sarrebruck-Commercy :fr:Jean III de Sarrebruck-Commercy|.
In 1269 Simon remarried, to Mathilde/Mahaut,, daughter of Simon III? of Sexfontaines and Elisabeth of Jonvelle, daughter of Guy III of Jonvelle. They had three known children:
Laure,, married in 1302 to Anseau of Joinville :fr:Anseau de Joinville|, son of Jean of Joinville :fr:Jean de Joinville|, and grandson of Simon, Seigneur of Joinville :fr:Simon de Joinville| with Beatrix of Auxonne :fr:Béatrice d'Auxonne|. They had one child:
*Jeanne, Dame of Rimaucourt. She married twice, to Aubert VII of Hangest :fr:Famille de Hangest|, Seigneur of Genlis, having one son that died as a child, and secondly Jean I of Noyers, Count of Joigny :fr:Joigny#Comte de Joigny pair de France et de Champagne|. His son Jean II succeeded him.
