From after events it is clear that he had already pledged himself to betray the king.

But his treachery was veiled with consummate art, and in spite of repeated warnings from Burgundy Edward remained unconcerned at the threats of invasion.

Of the Yorkist party he held himself secure since Warwick's desertion of their cause; of the Lancastrians he had little fear; and the powerful fleet of Duke Charles prisoned the Earl's ships in the Norman harbours.

Fortune however was with his foes.

A rising called Edward to the north in September, and while he was engaged in its suppression a storm swept the Burgundian ships from the Channel.