[...] Even the ample advances you made me on the publication of the Nibelung works were swallowed up in an expenditure which ceased to have any profitable relation to these works. As early as a year ago I was obliged to ask you to regard those advances as lost, as there was no possibility of recovering them by publication of the works themselves. I may think myself lucky not to see them published at all. For The Valkyrie, of which I am sending you a copy to-day, I can extract no more from my publisher than a very trifling deduction upon account of the advance he made me for The Mastersingers, a work which I am very far from having completed at present. Accordingly, though I now have to ask you to relinquish entirely your claims on my Nibelung works, I will not abandon the hope of being able some day to repay the advances themselves. This, of course, can only become possible through the generosity of my royal friends. But if I am to contemplate the repayment of even such friendly debts through him, I must necessarily await the favourable moment with patience and beg you to wait. [...] As to these works, however, which can never now bring me in the slightest profit from the public, they should and must belong to the King of Bavaria. I shall not allow even Tristan and Isolde ever to be performed elsewhere—and now, probably, never even in Munich itself. The Nibelungs can only be given to the nation by the King as a festival gift. As far as the ordinary world of the stage goes, its likes and dislikes, its bargaining and refusals to bargain, it is all over. I am sure, dear friend, you will understand me well, and will not misconstrue my very reasonable request when I ask you with all my heart to let the man who has made possible the completion and production of my Nibelungs have sole possession of whatever part of the whole is my work. Please understand me and be kind to me when I ask you to yield with a good grace to the King of Bavaria the original score of The Rhinegold, which is in your possession. The King should, and shall, hear of your rights in this work; I am certain that he will not let them go unindemnified. [...]
Source: Letters of Richard Wagner, Vol. 2, selected and ed. Wilhelm Altmann, trans. M. M. Bozman (J. M. Dent & Sons, 1927), No. 608