Archduke Rudolph, youngest son of Emperor Leopold II and youngest brother of Emperor Franz, was Beethoven's greatest patron.
As brother of the Emperor, Rudolph was able to gain access for Beethoven to the highest salons in Vienna.
Rudolph was himself a first-class musician. He was an excellent pianist and competent composer. He was the only pupil Beethoven ever took on as student of composition.
His works were frequently performed in his day, and can be heard today - though on CD rather than in live performance.
In 1809, when Beethoven accepted an invitation from King Jerome of Westphalia (brother of Napoleon Bonaparte) to become Kapellmeister at the court in Kassel, Archduke Rudolph persuaded Prince Lobkowitz and Prince Kinsky that they should pay Beethoven a guaranteed annual salary of 4000 florins - Rudolph contributing 1500 fl., Lobkowitz 700 fl., Kinsky 1800 fl. - on the sole condition that he abandon plans to move to Kassel and remain resident in Vienna for the rest of his life.
Beethoven agreed. Then, after the Austrian currency was devalued fivefold in 1811, Kinsky was thrown from his horse and died in 1812, and Lobkowitz went bankrupt and was forced to flee from Vienna in 1813.....Archduke Rudolph increased his payment at each stage to ensure Beethoven did not suffer financially.
In gratitude, Beethoven dedicated far more compositions to Rudolph than to anyone else - including the Fourth and Fifth (Emperor) Piano Concertos, the Piano Sonatas "Les Adieux", Hammerklavier and opus III, the Violin Sonata opus 96, the Archduke Piano Trio (named for Rudolph), the Missa Solemnis and the Grosse Fuge.
"Les Adieux" was specifically composed for Rudolph when he and the Imperial royal family were forced to leave Vienna in the face of the advancing French army in 1809. The first movement - Das Lebewohl [the Farewell] - was composed before Rudolph left; the second - Die Abwesenheit [the Absence] - was composed during his exile.
Beethoven told him he would not compose the third and final movement - Das Wiedersehen, [the Welcome Home] - until the Archduke returned to Vienna, which he duly did in 1810.
Archduke Rudolph asked Beethoven in March 1819 to compose a piece to be played at his enthronement as Archbishop of Olmütz a year later.
Beethoven embarked on the mighty sacred work, Missa Solemnis, which he didn't complete until 1823 - three years after Rudolph's enthronement!
Archduke Rudolph was an epileptic and sickly man; original plans for him to join the army were abandoned in favour of a less strenuous career in the church.
He died at the early age of 43, only four years after his great idol, Beethoven. He ordered that his heart should be removed from his body and placed in a niche of the cathedral at Olmütz, and that his body should be buried in the Imperial vault at St Stephen's cathedral in Vienna.