Louis; “you can do with me what you will.”  “You call yourself our prisoner,” said the Mussulman negotiators, “and so, we believe you are; but you treat us as if you had us in prison.”  The sultan perceived that he had to do with an indomitable spirit; and he did not insist any longer upon more than the surrender of Damietta, and on a ransom of five hundred thousand livres (that is, about ten million one hundred and thirty-two thousand francs, or four hundred and five thousand two hundred and eighty pounds, of modern money, according to M. de Wailly, supposing, as is probable, that livres of Tours are meant).  “I will pay willingly five hundred thousand livres for the deliverance of my people,” said Louis, and I will give up Damietta for the deliverance of my own person, for I am not a man who ought to be bought and sold for money.”  “By my faith,” said the sultan, the Frank is liberal not to have haggled about so large a sum.  Go tell him that I will give him one hundred thousand livres to help towards paying the ransom.”  The negotiation was concluded on this basis; and victors and vanquished quitted Mansourah, and arrived, partly by land and partly by the Nile, within a few leagues of Damietta, the surrender of which was fixed for the 7th of May.  But five days previously a tragic event took place.  Several emirs of the Mamelukes suddenly entered Louis’s tent.  They had just slain the Sultan Malek-Moaddam, against whom they had for some time been conspiring.  “Fear nought, sir,” said they to the king; “this was to be.  Do what concerns you in respect of the stipulated conditions, and you shall be free.”  Of these emirs one, who had slain the sultan with his own hand, asked the king, brusquely, “What wilt thou give me?  I have slain thine enemy, who would have put thee to death, had he lived;” and he asked to be made knight.  Louis answered not a word.  Some of the crusaders present urged him to satisfy the desire of the emir, who had in his power the decision of their fate.  “I will never confer knighthood on an infidel,” said Louis; “let the emir turn Christian; I will take him away to France, enrich him, and make him knight.”  It is said that, in their admiration for this piety and this indomitable firmness, the emirs had at one time a notion of taking Louis himself for sultan in the place of him whom they had just slain; and this report was probably not altogether devoid of foundation, for, some time afterwards, in the intimacy of the conversations between them, Louis one day said to Joinville, “Think you that I would have taken the kingdom of Babylon, if they had offered it to me?” “Whereupon I told him,” adds Joinville, “that he would have done a mad act, seeing that they had slain their lord; and he said to me that of a truth he would not have refused.”  However that may be, the conditions agreed upon with the late Sultan Malek-Moaddam were carried out; on the 7th of May, 1250, Geoffrey de Sargines gave up to the emirs the keys of Damietta;