At this time Edward was just becoming involved in a bitter quarrel with Philip the Fair, the young King of France. Philip coveted Aquitaine, and was determined to have it. He picked a quarrel with the King of England about the piratical doings of certain English seamen in the Channel. The mariners of the Cinque Ports and of Normandy had long been sworn foes; they fought whenever they met, without any concern as to whether England and France were at war or not. In 1293 there was a regular pitched battle between them, off St. Mahé, in Brittany; the Normans had the worse, and many of them were slain. This affray seemed to King Philip an admirable excuse for attacking his neighbour. He summoned Edward to Paris, as Duke of Aquitaine, to answer before his feudal lord for the misdoings of the English seamen. The King of England was not averse to giving satisfaction, and sent to offer to submit to an arbitration, in which the damages done by his subjects should be assessed. But Philip was not seeking damages, but an excuse for war; he at once declared Edward contumacious for not appearing in person, and proclaimed the forfeiture of the whole duchy of Aquitaine. Hardly realizing the French king's intentions, Edward despatched his brother Edmund, Earl of Lancaster, to endeavour to satisfy his offended suzerain. Philip then declared that he would consider himself satisfied if Edward surrendered into his hand, as a token of submission, the chief fortresses of Gascony: they should be restored the moment that compensation had been made for the doings at St. Mahé. Earl Edmund accepted the offer, and the castles were duly placed in Philip's hands. Then, with a barefaced effrontery that disgusted even his own nobles, the French king repudiated the agreement, and declared that he should retain Guienne permanently. Edward was thus committed to an unexpected war, while all his strongholds in Aquitaine were already in the enemy's hands. He began to arm in great wrath, and sent ambassadors abroad to gather allies among Philip's continental foes, chief of whom were the Emperor Adolf of Nassau and the Counts of Brabant, Holland, and Flanders. [Sidenote: =Alliance of Philip with the Welsh and Scots.=] But Philip also had looked about him for allies. At this moment Madoc-ap-Llewellyn rose in rebellion in North Wales, relying on French aid, and, what was of far greater importance, the discontent of the Scots took the form of open war with England. John Balliol embraced the French alliance, promised to wed his son to Philip's daughter, and sent raiding bands across the border to harry Cumberland and Northumberland. [Sidenote: =Edward invades Scotland.--Balliol gives up his crown.=]