Frederick III, Duke of Lorraine

Frederick III, called Ferry (1240–1303), only son of Matthias II and Catherine of Limburg, inherited Lorraine in 1251 aged eleven; his mother held the regency until 1255. That year he married Margaret of Champagne, daughter of King Theobald I of Navarre, tightening the duchy's ties to France. In the disputed royal election of 1257 he backed Alfonso X of Castile against Richard of Cornwall.

His quarrels with the bishops of Metz brought excommunication from Pope Clement IV in 1267 and an interdict on the duchy. He died on 31 December 1303 and was succeeded by his son Theobald.