King Charles V tried to remove the appanage system, but in vain. Provinces conceded in appanage tended to become "de facto" independent and the authority of the king was recognized there reluctantly. In particular the line of Valois Dukes of Burgundy caused considerable trouble to the French crown, with which they were often at war, often in open alliance with the English. Theoretically appanages could be reincorporated into the royal domain but only if the last lord had no male heirs. Kings tried as much as possible to rid themselves of the most powerful appanages. Louis XI retook the Duchy of Burgundy at the death of its last duke, Charles the Bold. Francis I confiscated the Bourbonnais, after the treason in 1523 of his commander in chief, Charles III, Duke of Bourbon, the 'constable of Bourbon' (died 1527 in the service of Emperor Charles V).