After the destruction of several strongholds of Margaret and a defeat of her forces at two sea battles in 1351, Edward III of England, Margaret's brother-in-law through her sister Philippa of Hainault, came to her aid, winning a naval engagement off Veere in 1351; a few weeks later the Hooks and their English allies were defeated by William and the Cods at Vlaardingen, a defeat which ruined Margaret's cause. Edward III shortly afterwards changed sides and in 1354, Margaret saw herself compelled to come to an understanding with her son: he being recognized as count of Holland and Zeeland, and she being secured as ruling countess of Hainault in her lifetime. A partially destroyed parchment dated 7 December 1354 at Mons, with four broken seals appended, announces that John of Hainaut and Wallerand of Luxemburg, Lord of Ligny, acting as intermediaries and arbitrators, to reestablish the peace between Margaret and her son, the Duke, William of Bavaria (the future William III, Count of Hainaut), make known the terms of the arbitration settlement stated in previous deeds, which they uphold : ".. In execution of the said settlement, the Countess Margaret (II) of Hainaut, etc. cedes to her son William, Duke of Bavaria the counties of Hainaut, Holland, Zeeland and the lordship of Frisia, in return taking payment of 40000 Florence Florins and widow's pension of 7000 florins; for his part the said Duke waives his rights over Hainaut so long as his mother is living. - G Wymans, " Inventaire analytique du chartrier de la