During fourteen years, from 1314 to 1328, three sons of Philip IV reigned in rapid succession; but with the death of the last the main line of the House of Capet came to an end, and the crown passed to his nephew and namesake Philip of Valois.[26] The latter declared that his claims were based on a clause of the old Salic Law[27] forbidding a woman to inherit landed property, because as it happened Philip IV had left a daughter Isabel, who had married Edward II of England, and their son Edward III loudly protested that his right to the throne of France was stronger than that of the Valois. The Salic Law, Edward maintained, might prevent a woman from succeeding to the throne, but there was nothing in this restriction to forbid the inheritance passing to her male heirs. [Sidenote: Causes of the Hundred Years’ War] The question of the Salic Law is important because its different interpretations were the immediate excuse for opening hostilities between England and France in that long and weary struggle called the ‘Hundred Years’ War’. There were of course other and far deeper reasons. One of these reasons was that English kings had never forgotten or forgiven John’s expulsion from Normandy. They wanted to avenge this ignominious defeat and also Philip IV’s encroachments in the Duchy of Guienne, that, united to his policy of supporting the Scottish chieftains in their war of independence, had been a steady source of disaster to England since the beginning of the fourteenth century. Because of his failure in Scotland and the revolts of his turbulent barons Edward II was murdered; and Edward III, taking warning from his father’s fate, welcomed the war with France, not merely in the hope of revenge and glory, but still more in order to find an occupation for the hot English blood that might otherwise in the course of its embittered feuds murder him.