The disorders and dissensions to which France was a prey, the presumptuous and hare-brained incapacity of her new king, were, for so ambitious and able a prince as Edward III., very strong temptations.
Nor did opportunities for attack, and chances of success, fail him any more than temptations.

He found in France, amongst the grandees of the kingdom, and even at the king's court, men disposed to desert the cause of the king and of France to serve a prince who had more capacity, and who pretended to claim the crown of France as his lawful right.

The feudal system lent itself to ambiguous questions and doubts of conscience: a lord who had two suzerains, and who, rightly or wrongly, believed that he had cause of complaint against one of them, was justified in serving that one who could and would protect him.

Personal interest and subtle disputes soon make traitors; and Edward had the ability to discover them and win them over.

The alternate outbursts and weaknesses of John in the case of those whom he suspected; the snares he laid for them; the precipitancy and cruel violence with which he struck them down, without form of trial, and almost with his own hand, forbid history to receive his suspicious and his forcible proceedings as any kind of proof; but amongst those whom he accused there were undoubtedly traitors to the king and to France.