Friedrich Daniel Rudolf Kuhlau was born on 11 September 1786 just south of Lüneburg in Lower Saxony, into a poor family of military oboists — father, grandfather and uncle alike — who nevertheless paid for his piano lessons. At seven he slipped on ice and lost his right eye. In 1802 he moved to Hamburg to study piano with C. F. G. Schwencke, made his debut in 1804 and began writing songs and chamber music for money. In 1810 he fled to Copenhagen to escape conscription into the Napoleonic army and published his first piano and flute pieces the same year; he taught piano there, was appointed an unsalaried court musician in 1812 and became a Danish citizen in 1813. He visited Vienna in 1821 and 1825 and became a friend of Beethoven, whose music he had already been introducing to Copenhagen audiences, and was made an honorary professor in 1828. He died on 12 March 1832.

His breakthrough came at the Royal Danish Theatre in 1814 with the singspiel Røverborgen, on a libretto by Adam Oehlenschläger, which won him a well-paid post as singing teacher at the theatre in 1816; Trylleharpen, Elisa and Hugo og Adelheid all failed, and Lulu of 1824 restored him. His greatest success was the music for Elverhøj in 1828, taken as the first work of Danish National Romanticism and as a tribute to the monarchy, and it made him a fixture of the Danish Golden Age. A great deal of his music is for the flute, an instrument he did not play. His house burned down with all his unpublished manuscripts in it, and he still left more than two hundred published works across most genres.

Sources:

• https://en.wikipedia.org/wiki/Friedrich_Kuhlau
• https://www.wikidata.org/wiki/Q157865