The defeat of Poitiers and the capture of John the Good in 1356 deprived Joan of John's support and Yolande retook the regency. Robert was knighted in December 1356 and declared of age on 8 November 1359. He assisted at the coronation of Charles V of France at Reims on 9 May 1364, then at that of Charles VI of France on 4 November 1380. During Charles V's reign he fought in several engagements in 1374 during the campaign to eject the English from Normandy. In 1401, Robert ceded his duchy to his son Edward, but reserved the usufruct on it, bypassing his grandson Robert (son of Henry of Bar). The younger Robert unsuccessfully opposed this in the parliament of Paris that ran from 1406 to 1409. Charles VI's madness put him under the control of the Duke of Orleans and Duke of Burgundy. The elder Robert supported the duke of Orleans, and after that duke's assassination was more and more inclined to remain within his duchy. In his later years he suffered from attacks of gout that prevented him from walking.