Simon I, Duke of Lorraine

Simon I (1076 – 13 or 14 January 1139) was the duke of Lorraine from 1115 to his death, the eldest son and successor of Theodoric II and Hedwig of Formbach and a half-brother of Emperor Lothair III.

Continuing the policy of friendship with the Holy Roman Emperor, he accompanied the Emperor Henry V to the Diet of Worms of 1122, where the Investiture Controversy was resolved.

He had stormy relations with the episcopates of his realm: fighting with Stephen of Bar, bishop of Metz, and Adalberon, archbishop of Trier, both allies of the count of Bar, whose claim to Lorraine against Simon's father had been quashed by Henry V's father Henry IV. Though Adalberon excommunicated him, Pope Innocent II lifted it. He was a friend of Bernard of Clairvaux and he built many abbeys in his duchy, including that of Sturzelbronn in 1135. There was he interred after his original burial in Saint-Dié.

Children of Simon and Adelaide Simon I of Lorraine married his step-sister, Adelaide, daughter of Henry III of Leuven. Their children were: Matthias, his successor in Lorraine Robert, lord of Floranges (near Thionville) Agatha of Lorraine, married Reginald III, Count of Burgundy (Renaud III), the first Free Count Hedwige, married Frederick III, count of Toul Bertha, married Margrave Hermann III of Baden Mathilde, married Gottfried I, Count of Sponheim Baldwin John