Now, in 1337 Edward began to think of reviving his dormant pretensions to the French crown, though they had two fatal defects. The first was that there had never been any precedent in France for a claim through the female line. The second was that, even if such descents could be counted, one of his mother's brothers had left a daughter, the Queen of Navarre, and the son of that princess had a better female claim than Edward himself. The only way in which this defect could be ignored was by pleading, like Bruce in 1292, that Edward was a generation nearer to the old royal stock than his cousin, Charles, King of Navarre. [Sidenote: =Edward claims the French crown.=] On this rather futile plea Edward laid solemn claim to the French crown, and declared Philip of Valois a usurper. Perhaps there may be truth in the story which tells that he did not do so from any strong belief in his own theory, but because the Flemings, vassals to the French crown, had declared that they could not aid him, though willing to do so, on account of oaths of fealty sworn to the King of France. If Edward claimed to be king himself, they said, their allegiance and help would be due to him. Whether the tale be true or not, he at any rate made the claim. In reliance on the assistance of the Flemings, and of their neighbours the Dukes of Brabant and Holland, and with the countenance of the Emperor, Lewis of Bavaria, King Edward determined to land in the Low Countries and attack France from the north. He called out great bodies of soldiery, and took advantage of the devotion that the nation felt for him to raise illegal taxes for their pay. Violating his grandfather's engagements, he took a "tallage" from the towns, and levied a "_mal-tolt_" or extra customs-duty on the export of wool. In the excitement of the moment, little opposition was made to these high-handed measures. [Sidenote: =First campaign.--Naval victory off Sluys.=]