Frederick III (French: Ferry) (1240 – 31 December 1302) was the Duke of Lorraine from 1251 to his death. He was the only son and successor of Matthias II and Catherine of Limburg. He was not yet thirteen years of age when his father died, so his mother assumed the regency for a few years. In 1255, he married Margaret, the daughter of King Theobald I of Navarre and Margaret of Bourbon. Frederick's father-in-law was the Count of Champagne as well, and the marriage of Margaret with Frederick signified the Gallicization of Lorraine and the beginnings of tension between French and German influences which characterises its later history. When Joan I of Navarre, Margaret's niece, (the daughter of her brother, Henry I of Navarre), married Philip the Fair, the future king of France, in 1284, the ti