It is my pet theory that Beethoven was an admirer of Napoleon until his death.
Beethoven in 1804
Beethoven, like many contemporary Romatic artists of his time, was a great admirer of Napoleon. A story by Ferdinand Ries tells of Beethoven's rejection of Napoleon upon the latter's assumption of the title of emperor:
In writing this symphony [Symphony No. 3] Beethoven had been thinking of Buonaparte, but Buonaparte while he was First Consul. At that time Beethoven had the highest esteem for him and compared him to the greatest consuls of ancient Rome. Not only I, but many of Beethoven's closer friends, saw this symphony on his table, beautifully copied in manuscript, with the word "Buonaparte" inscribed at the very top of the title-page and "Ludwig van Beethoven" at the very bottom. …I was the first to tell him the news that Buonaparte had declared himself Emperor, whereupon he broke into a rage and exclaimed, "So he is no more than a common mortal! Now, too, he will tread under foot all the rights of man, indulge only his ambition; now he will think himself superior to all men, become a tyrant!" Beethoven went to the table, seized the top of the title-page, tore it in half and threw it on the floor. The page had to be re-copied and it was only now that the symphony received the title "Sinfonia eroica."
Ferdinand Ries wrote this in his recollection of Beethoven in 1837 -- 10 year after Beethoven's death. This is my first problem with the story: its lack of authenticity.
I find it hard to believe that Beethoven would cease to admire Napoleon once he assume the title of emperor. It is a trivial detail for someone who admired the causes and ideals of liberation represented by Napoleon. None of Napoleon's admirers had a problem with this. Byron remained an admirer all his life.
Futhermore, even after changing the title of his work to "Eroica", Beethoven wrote to his publisher on 26 August of 1804 that "the title of the symphony is really Bonaparte." Now Napoleon assumed the title of emperor in May 1804 (he was crowned in December) and Ferdinand Ries account is doubious.
What we do know is that Beethoven did change the title of his symphony and he rededicated his work to Prince Franz Joseph Maximillian Lobkowiz (he had problem with emperors but not princes, if we were to believe Ries). My theory is that it wasn't because of his disillusion with Napoleon. It was changed because it simply wasn't politically correct to dedicate a piece of music to Napoleon at that time and that place.
Second to England, Austro-Hungary was the revolution's greatest enemy. The symphony premiered privately at Lobkowitz's castle in 1804, was publicly performed in April 1805, and published in October 1806. Very sensitive time indeed for France and Austro-Hungary. Beethoven lived in Vienna and all his patrons were aristocrats. He could not hope to maintain his career after openly declaring his political beliefs. Beethoven was still an admirer after 1804, he only went into the closet.
Ries' account was confirmed by Anton Schindler. However, Schindler's creditability was cast into doubt as he has been known to have doctored several of Beethoven's papers, including an episode of Bernadotte meeting the composer.
A paper discusses this in great depth: Did Napoleon Remain Beethoven's "Hero?"