Otto was now thrown back on Saxony and the lower Rhineland. He again took up his quarters with the faithful citizens of Cologne, whence he appealed for help to his uncle, John of England, still under the papal ban. With English help he united the princes of the Netherlands in a party of opposition to the Pope and the Hohenstaufen. Frederick answered by a closer and more effective league with France. Even before his coronation he had met Louis, the son of Philip Augustus, at Vaucouleurs. All Europe seemed arming at the bidding of the Pope and Emperor. John of England now hastily reconciled himself to Innocent, at the price of the independence of his kingdom. He thus became in a better position to aid his excommunicated nephew, and revenge the loss of Normandy and Anjou on Philip Augustus. His plan was now a twofold one. He himself summoned the barons of England to follow him in an attempt to recover his ancient lands on the Loire. Meanwhile, Otto and the Netherlandish lords were encouraged, by substantial English help, to carry out a combined attack on France from the north. The opposition of the English barons reduced to comparative insignificance the expedition to Poitou, but a very considerable army gathered together under Otto, and took up its position in the neighbourhood of Tournai. Among the French King’s vassals, Ferrand, Count of Flanders, long hostile to his overlord Philip, and the Count of Boulogne, fought strenuously on Otto’s side; while, of the imperial vassals, the Count of Holland and the Duke of Brabant [Lower Lorraine] were among Otto’s most active supporters. A considerable English contingent came also, headed by Otto’s bastard uncle, William Longsword, Earl of Salisbury. Philip himself commanded the chivalry of France, leaving his son Louis to fight against John in Poitou. On 27th July the decisive battle was fought at Bouvines, a few miles south-west of Tournai. [Sidenote: Battle of Bouvines, 1214.] The army of France and the Church gained an overwhelming victory over the league which had incurred the papal ban, and Otto’s fortunes were utterly shattered. He soon lost all his hold over the Rhineland, and was forced to retreat to the ancient domains of his house in Saxony. His remaining friends made their peace with Philip and Frederick. The defection of the Wittelsbachers lost his last hold in the south of Germany, and the desertion of Valdemar of Denmark deprived him of a strong friend in the north. John withdrew from continental politics to be beaten more decisively by his barons than he had been beaten in Poitou or at Bouvines. By the summer of 1215, Aachen and Cologne had opened their gates to Frederick, who repeated his coronation in the old chapel of Charlemagne. Before Otto’s death in 1218 his power was confined to Brunswick and the region of the Harz. [Sidenote: The fall of the Guelfs and the triumph of Innocent.] His brother Henry delivered up the imperial insignia to the conqueror, and received a confirmation of