Prince John, in league with Philip of France , Coeur-de-Lion’s mortal enemy, was using every species of influence with the Duke of Austria , to prolong the captivity of his brother Richard, to whom he stood indebted for so many favours. In the meantime, he was strengthening his own faction in the kingdom, of which he proposed to dispute the succession, in case of the King’s death, with the legitimate heir, Arthur Duke of Brittany