Philip of Burgundy
On 11 July 1423, Arnold, still a boy, succeeded Duke Reinald IV. Arnold was the grandson of Reinald's sister, Johanna. Although the Emperor Sigismund had invested the Duke of Berg with the duchy of Gelders, Arnold retained the confidence of the Estates by enlarging their privileges, and enjoyed the support of Duke Philip of Burgundy. Arnold was betrothed, and afterwards united in marriage to Catherine of Cleves, a niece of Philip of Burgundy. Subsequently, however, Duke Arnold fell out with his ally as to the succession to the see of Utrecht, whereupon Philip joined with the four chief towns of Guelders in the successful attempt of Arnold's son Adolf to substitute his own for his father's authority. Arnold gave up his claim on Jűlich only after his defeat in 1444 by Gerhard VII, Duke of Jülich-Berg.