An unexpected incident led to its recommencement in spite of the truce: not, however, throughout France or directly between the two kings, but with fiery fierceness, though it was limited to a single province, and arose not in the name of the kingship of France, but out of a purely provincial question. John III., Duke of Brittany and a faithful vassal of Philip of Valois, whom he had gone to support at Tournay “more stoutly and substantially than any of the other princes,” says Froissart, died suddenly at Caen, on the 30th of April, 1341, on returning to his domain. Though he had been thrice married, he left no child. The duchy of Brittany then reverted to his brothers or their posterity , but his very next brother, Guy, Count of Penthievre, had been dead six years, and had left only a daughter, Joan, called the Cripple, married to Charles of Blois, nephew of the King of France. The third brother was still alive; he too was named John, had from his mother the title of Count of Montfort, and claimed to be heir to the duchy of Brittany in preference to his niece Joan. The niece, on the contrary, believed in her own right to the exclusion of her uncle. The question was exactly the same as that which had arisen touching the crown of France when Philip the Long had successfully disputed it with the only daughter of his brother Louis the Quarreller; but the Salic law, which had for more than three centuries prevailed in France, and just lately to the benefit of Philip of Valois, had no existence in the written code, or the traditions of Brittany. There, as in several other great fiefs, women had often been recognized as capable of holding and transmitting sovereignty. At the death of John III., his brother, the Count of Montfort, immediately put himself in possession of the inheritance, seized the principal Breton towns, Nantes, Brest, Rennes, and Vannes, and crossed over to England to secure the support of Edward III. His rival, Charles of Blois, appealed to the decision of the King of France, his uncle and natural protector. Philip of Valois thus found himself the champion of succession in the female line in Brittany, whilst he was himself reigning in France by virtue of the Salic law, and Edward III. took up in Brittany the defence of succession in the male line which he was disputing and fighting against in France. Philip and his court of peers declared on the 7th of September, 1341, that Brittany belonged to Charles of Blois, who at once did homage for it to the King of France, whilst John of Montfort demanded and obtained the support of the King of England. War broke out between the two claimants, effectually supported by the two kings, who nevertheless were not supposed to make war upon one another and in their own dominions. The feudal system sometimes entailed these strange and dangerous complications.