[...] Here is a novelty for you, which will bring you luck, and on behalf of which I count on your good offices. I am sending you a piece which, in the opinion of people who have heard it, will usurp the place of the Tannhäuser March. Let it be called The March of the Young King of Bavaria. What I send you to-day is the score as for a big military band. Any skilled bandmaster could adapt this for a smaller band. I am about to orchestrate it for an ordinary string orchestra, and will send you this arrangement in a week or a fortnight. Two-handed and four-handed pianoforte arrangements by H. von Bülow are enclosed. I count on its being performed at open-air and military concerts and later, by the very nature of the piece (which Madame your wife's mastery of the pianoforte will speedily interpret to you), on its attaining widespread popularity. [...]
Source: Letters of Richard Wagner, Vol. 2, selected and ed. Wilhelm Altmann, trans. M. M. Bozman (J. M. Dent & Sons, 1927), No. 601