Frederick III was the Count of Bar and Duke of Upper Lorraine from the death of his father, Frederick II

Frederick II, Duke of Upper Lorraine

Frederick II , son of Thierry I and Richilde von Blieskastel, daughter of Folmar III, Count in Bliesgau; was the count of Bar and duke of Lorraine, co-reigning with his father from 1019....

, in 1026 or 1027 to his own death. His mother was Matilda, daughter of Herman II, Duke of Swabia

Herman II, Duke of Swabia

Herman II was the Conradine duke of Swabia from 997 to his death, as the son of and successor Conrad I.Herman opposed the election of Henry IV, Duke of Bavaria, as king of Germany because he himself had been a contender...

.

His father had been co-duke since 1019 and his grandfather, Thierry I

Thierry I, Duke of Upper Lorraine

Theodoric I was the count of Bar and duke of Upper Lorraine from 978 to his death. He was the son and successor of Frederick I and Beatrice, daughter of Hugh the Great, count of Paris, and sister to the French king Hugh Capet.His mother was the regent until 987...

, continued to reign until his own death in 1027 or 1028. His reign is completely obscure. Even his regent

Regent

A regent, from the Latin regens "one who reigns", is a person selected to act as head of state because the ruler is a minor, not present, or debilitated. Currently there are only two ruling Regencies in the world, sovereign Liechtenstein and the Malaysian constitutive state of Terengganu...

 is unknown. He died young and his county passed to his sister Sophia while Lorraine was given to Gothelo I, Duke of Lower Lorraine.