Two days before the Prince's birth a secret treaty between the Emperor and King Henry was concluded at Whitehall. Chapuys had at length attained the object of his untiring efforts, and De Courrières was sent from Spain on a confidential mission to induce Henry to declare war against France. The defeat of the Duke of Aerschot at Sittard excited general alarm in Flanders, and Mary was at her wits' end for money and men. But the Emperor himself was hastening across the Alps to the help of his loyal provinces. The marriage of his son Philip with the Infanta of Portugal had been finally settled, and with the help of this Princess's large dowry and another half-million of Mexican gold, Charles was able to raise a large army of German and Italian troops. On the 22nd of August he appeared in person before Düren, the capital of Cleves, which surrendered within a week. The Duke threw himself on the victor's mercy, and was pardoned and invested anew with his hereditary duchies, while Guelders was annexed to the Netherlands and the Prince of Orange became its first Governor. William of Cleves on his part renounced the French alliance, and agreed to marry one of King Ferdinand's daughters. His previous marriage with Jeanne d'Albret was annulled by the Pope, and this resolute young Princess had the satisfaction of carrying her protest into effect. Encouraged by these successes, Charles now laid siege to Landrécy, the capital of Hainault, which had been captured and fortified by the French, and was joined by a gallant company of English under Lord Surrey and Sir John Wallop. "Par ma foi!" exclaimed the Emperor, as he rode down their ranks, "this is a fine body of gentlemen! If the French King comes, I will live and die with the English."[348] But Francis refused to be drawn into a battle, and the approach of winter made both armies retire from the field.