Charles IV of France
He accompanied John de Warenne, 7th Earl of Surrey and Queen Isabella in their negotiations with King Charles IV of France in Gascony in March 1325. Rather than returning to England Isabella stayed in France where she embarked upon an affair with Roger Mortimer, 1st Earl of March and formed a plot to oust her husband, Edward II, from the throne. The plot was successful and Isabella called a Parliament in January 1327, which was attended by John Marmion, and which ratified Isabella's eldest son Edward III as the new king.