In 1802 and 1803 Beethoven was working on his third symphony, a work initially intended as a tribute to Napoleon. On the news in 1804 that Napoleon had been crowned Emperor, he is said to have destroyed the first page, with its dedication, seeing in his former republican hero a man who was like the rest. For the last movement of what is now known as the Eroica Symphony Beethoven presented a set of seven variations and a fugue, using a theme he had written for Salvatore Viganò's ballet The Creatures of Prometheus in 1801.

The Fifteen Variations and Fugue in E flat major on an Original Theme, Op. 35, using the Prometheus theme and written in 1802, have long been known as the Eroica Variations, a title borrowed from the symphony. The work was dedicated to count Moritz Lichnowsky, brother of Beethoven's generous patron Prince Karl Lichnowsky. In an Introduction the bass of the theme is heard, followed by a version a due, the bass in the left hand. In the next version, a tre, the bass is in the right hand, while the left adds a counterpoint above and below. The following version, a quattro, has the original bass in the upper part in a more elaborate texture. This leads to the familiar theme itself.

The first variation of the theme offers a semiquaver right-hand version of the theme, followed by a triplet semiquaver version, including a brief cadenza. An abrupt third variation leads to a fourth with a running semiquaver left-hand part and right-hand chords, with a syncopated fifth variation. The theme is heard with great clarity in the sixth variation, while the seventh is in canon at the octave. The hand-crossing of the eighth variation is succeeded by a ninth version in which the bass of the theme is heard in lower register grace notes while the tenth brings a division of labor. The following three variations explore other keyboard sonorities before the penultimate E flat minor fourteenth version and the ornamented Largo of the E flat major fifteenth. The fugal subject, the bass of the theme, is announced by the second voice, answered by the upper voice and followed by a third entry in the lower register. The fugal texture is interrupted by a passage that leads to the return of the full theme and its subsequent elaboration in a brilliant conclusion.