Schumann wrote the Fantasie in C Major, Op. 17 in 1836. It was revised prior to publication in 1839, when it was dedicated to Franz Liszt. It is generally described as one of Schumann's greatest works for solo piano.
Schumann prefaced the work with a quote from Friedrich Schlegel:
Durch alle Töne tönet
Im bunten Erdentraum
Ein leiser Ton gezogen
Für den, der heimlich lauschet.
("Resounding through all the notes/In the earth's colorful dream/There sounds a faint long-drawn note/For the one who listens in secret.")
The musical quotation of a phrase from Beethoven's song cycle An die ferne Geliebte in the coda of the first movement was not acknowledged by Schumann, and apparently was not spotted until 1910. The text of the passage quoted is: Accept then these songs [beloved, which I sang for you alone]. Both the Schlegel stanza and the Beethoven quotation are appropriate to Schumann's current situation of separation from Clara Wieck. Schumann wrote to Clara: "The first movement may well be the most passionate I have ever composed – a deep lament for you." They still had many tribulations to suffer before they finally married four years later.