The quick, hard blow did its work.

The young Earl of March betrayed the plans of his partizans to purchase pardon.

The Breton fleet, which had defeated an English fleet in the Channel and made a descent upon Plymouth, withdrew to its harbours; and though the Duke of Burgundy was on the point of commencing the siege of Calais the plans of an attack on that town were no more heard of.
[Sidenote: Henry's difficulties] But the difficulty of Wales remained as great as ever.

The discouragement of Owen at the failure of the conspiracy of the Percies was removed by the open aid of the French Court.

In July 1404 the French king in a formal treaty owned Glyndwr as Prince of Wales, and his promises of aid gave fresh heart to the insurgents.