In 1270, Louis IX, although very weakened physically, undertook a new crusade with his three sons. Any enthusiasm Joinville had for the previous crusade had been knocked out of him, and he refused to follow Louis, recognizing the uselessness of the enterprise and convinced that the duty of the king was not to leave the kingdom that needed him. In fact, the expedition was a worse disaster than its predecessor and the king died of dysentery outside Tunis on August 25, 1270.