Beethoven hated the nickname 'The Emperor' for his Fifth Piano Concerto because he strongly opposed Napoleon Bonaparte.

Ludwig van Beethoven composed his Piano Concerto No. 5 in E-flat major, Op. 73, between 1809 and 1811. This period coincided with the War of the Fifth Coalition, during which Napoleon Bonaparte’s forces laid siege to Vienna in May 1809. The composer famously sought refuge in the cellar of his brother Caspar Anton Carl's house, where he used pillows to cover his ears and protect his remaining hearing from the thunderous artillery fire.The nickname 'The Emperor' did not originate with Beethoven and is entirely absent from his original scores. Historical evidence suggests the title was popularized by Johann Baptist Cramer, a London-based publisher who believed the concerto’s grand structure and heroic themes demanded a regal name. Beethoven’s personal politics were famously anti-monarchical, especially after Napoleon declared himself Emperor of the French in 1804. This event led Beethoven to famously scratch out the dedication to Napoleon on his Third Symphony, the 'Eroica.'Musically, the concerto was revolutionary for its time because it begins with a written-out cadenza for the piano rather than waiting for the end of the movement. It premiered in Leipzig at the Gewandhaus in 1811, but the Viennese premiere in 1812 was less successful due to the ongoing social unrest. Today, the work is considered the pinnacle of the 'heroic' style of the middle period of Beethoven's career. Despite the composer's likely disdain for the title, it remains one of the most frequently performed concertos in the classical repertoire.