There followed the long Navarrese Civil War, with alternations of success and defeat, ending only with the death of the prince of Viana, possibly by poison administered by his father in 1461. The Catalans, who had adopted the cause of Charles and who had grievances of their own, called in a succession of foreign pretenders in a War against John II. His last years John spent contending with these. He was forced to pawn Roussillon, his possession on the north-east of the Pyrenees, to King Louis XI of France, who refused to part with it.