The overthrow of Charles the Bold was the second great task of Louis XI. This he accomplished by a policy much like that of Pitt against Napoleon. Louis was the soul of all hostile coalitions, especially urging on the Swiss and Sigismund of Austria, who ruled Tirol and Alsace. Charles's ally, Edward IV., invaded France in June 1475, but Louis bought him off on the 29th of August at Picquigny--where the two sovereigns met on a bridge over the Somme, with a strong grille between them, Edward receiving 75,000 crowns, and a promise of a pension of 50,000 crowns annually. The dauphin Charles was to marry Edward's daughter. Bribery of the English ministers was not spared, and in September the invaders recrossed to England. The count of Saint Pol, who had continued to play his double part, was surrendered by Charles to Louis, and executed, as was also Jacques d'Armagnac, duke of Nemours. With his vassals terrorized and subdued, Louis continued to subsidize the Swiss and René II. of Lorraine in their war upon Charles. The defeat and death of the duke of Burgundy at Nancy on the 5th of January 1477 was the crowning triumph of Louis' diplomacy. But in his eagerness to seize the whole inheritance of his rival, Louis drove his daughter and heiress, Mary of Burgundy, into marriage with Maximilian of Austria (afterwards the emperor Maximilian I.), who successfully defended Flanders after a savage raid by Antoine de Chabannes. The battle of Guinegate on the 7th of August 1479 was indecisive, and definite peace was not established until after the death of Mary, when by the treaty of Arras (1482) Louis received Picardy, Artois and the Boulonnais, as well as the duchy of Burgundy and Franche Comté. The Austrians were left in Flanders, a menace and a danger. Louis failed here and in Spain; this failure being an indirect cause of that vast family compact which surrounded France later with the empire of Charles V. His interference in Spain had made both John II. of Aragon and Henry IV. of Castile his enemies, and so he was unable to prevent the marriage of their heirs, Ferdinand and Isabella. But the results of these marriages could not be foreseen, and the unification of France proved of more value than the possession of so widespread an empire. This unification was completed (except for Brittany) and the frontiers enlarged by the acquisition, upon the death of René of Anjou in 1480, of the duchies of Anjou and Bar, and in 1481 of Maine and Provence upon the death of Charles II., count of Maine. Of the inheritance of the house of Anjou only Lorraine escaped the king.