His mother was Mary, daughter of Guy I of Blois.During his long minority, the regency was in the hands of his mother and Eberhard III of Württemberg.
In December 1353, John did homage for the duchy to Charles IV, Holy Roman Emperor, who made him lieutenant-general of the Empire in the Moselle country.
He survived, however, unlike his father, to fight again, although he was taken prisoner by the English.
He later fought on the side of the Dauphin Charles in putting down the Parisian rebellion of Étienne Marcel.
He attended Charles' coronation on 19 May 1364 in Rheims, strengthening the ties to France which had steadily been building in Lorraine for the past century.
He entered the War of the Breton Succession, as had his father, to aid his uncle Charles of Blois against John of Montfort.
Partly this was due to the free companies ravaging his lands and in part the royal officials who tried to litigate the relationship between John (an Imperial vassal) and his vassals.
In the end, he entered into rapprochement with Philip II, Duke of Burgundy.