The truce with France lasted for two years after the death of Duke Humphrey, and came to an end partly owing to the eagerness of the French to push their advantages, but much more from the treachery and bad faith of Suffolk and Somerset, who gave the enemy an admirable _casus belli_. By their weakness, or perhaps with their secret connivance, the English garrisons of Normandy carried out plundering raids of the most impudent sort on French territory. When summoned to punish the offenders, and to make monetary compensation, Suffolk and Somerset shuffled and prevaricated, but gave no satisfaction. Thereupon the French king once more declared war (July 1449) and invaded Normandy. Somerset was in command; he showed hopeless incapacity and timidity, and in a few months the duchy which had been so long held by the swords of Bedford, York and Shrewsbury was hopelessly lost. The final blow came when a small army of relief sent over from England was absolutely exterminated by the French at the battle of Formigny (April 15, 1450). Somerset, who had retired into Caen, surrendered two months later after a feeble defence, and the English power in northern France came to an end.
Even before this final disaster the indignation felt against Suffolk and Somerset had raised violent disturbances at home. Suffolk was impeached on many charges, true and false; it was unfair to accuse him of treason, but quite just to lay double-dealing and bad faith to his charge. The king tried to save him from the block by banishing him before he could be tried. But while he was sailing to Flanders his ship was intercepted by some London vessels, which were on the look-out for him, and he was deliberately murdered. The instigators of the act were never discovered. But, though Suffolk was gone, Somerset yet survived, and their partisans still engrossed the confidence of the king. To clear out the government, and punish those responsible for the late disasters, the commons of Kent rose in insurrection under a captain who called himself John Mortimer, though his real name seems to have been John Cade. He was a soldier of fortune who had served in the French wars, and claimed to be in the confidence of the duke of York, the person to whom the eyes of all who hated Somerset and the present régime were now directed.