But Edward was guided by weightier considerations than this.

In spite of his victory at Sluys the superiority of France at sea had been a constant embarrassment.

From this difficulty the capture of Calais would do much to deliver him, for Dover and Calais together bridled the Channel.

Nor was this all.

Not only would the possession of the town give Edward a base of operations against France, but it afforded an easy means of communication with the only sure allies of England, the towns of Flanders.