More than a century later, Philip II of Spain attempted to claim the French crown for his daughter Isabella Clara Eugenia, born of his Valois queen. Philip's agents were instructed to "insinuate cleverly" that the Salic law was a "pure invention". But even if the "Salic law" did not really apply to the throne of France, the very principle of agnatic succession had become a cornerstone of the French royal succession; they had upheld it in the Hundred Years' War with the English, and it had produced their kings for more than two centuries. The eventual recognition of Henry IV, the first of the Bourbons kings, further solidified the agnatic principle in France.