The temptation was too great for France to resist; and in the early spring of 1521 French forces overran Navarre, and restored to his kingdom the exile D'Albret.
Francis had many plausible excuses, and sought to prove that he was not really the aggressor.

There had been confused fighting between the imperialist Nassau and Francis's allies, the Duke of Guelders and Robert de la Marck, which the imperialists may have begun.

But Francis revealed his true motive, when he told Fitzwilliam that he had many grievances against Charles and could not afford to neglect this opportunity for taking his revenge.[401] [Footnote 400: _Ibid._, iii., 883, 891, 964, 976, 988, 994.] [Footnote 401: _L.

and P._, iii., 1303, 1310, 1315.] * * * * * War between Emperor and King soon spread from Navarre to the borders of Flanders and to the plains of Northern Italy.

Both sovereigns claimed the assistance of England in virtue of the Treaty of London.
But Henry would not be prepared for war till the following year at least; and he proposed that Wolsey should go to Calais to mediate between the two parties and decide which had been the aggressor.
Charles, either because he was unprepared or was sure of Wolsey's support, readily agreed; but Francis was more reluctant, and only the knowledge that, if he refused, Henry would at once side with Charles, induced him to consent to the conference.