Guillaume Ier de Mont-Saint-Jean

• 
• Born circa 1170 in Mont-Saint-Jean
• Deceased on April 7, 1223, at the approximate age of 52 years

Parents

• Hugues II de Mont-Saint-Jean (c. 1128 - 1196), chevalier, seigneur de Mont-Saint-Jean
• Élisabeth de Vergy (c. 1130 - 1196), dame en partie de Vergy

Family

• Married with Bure d'Ancy-le-Franc (1146 - 1215), dame d'Ancy-le-Franc, issuing
  • Guillaume II ( - aft. 1233)
  • Élisabeth (1192 - aft. 1219)