de varier, a large-scale variation cycle (composed in 1803/04 for Prince Louis Ferdinand), and the treatise Practische Beispiele (published in 1803), which contained 24 compositions. 1806–1836: Departure from Vienna and life in Paris Reicha's life and career in Vienna were interrupted by Napoleon's November 1805 occupation of the city by French troops. In 1806 Reicha travelled to Leipzig to arrange a performance of his new work, the cantata Lenore (stopping at Prague to see his mother for the first time since 1780), but because Leipzig was blockaded by the French, not only was the performance cancelled but he could not return to Vienna for several months. When he did return it was not for long, because by 1808 the Austrian Empire was already preparing for another war, the War of the Fifth Coalition, so Reicha decided to move back to Paris. He was soon teaching composition privately, future prolific composer George Onslow being one of his pupils by 1808. This time three of his many operas were produced, but they all failed; yet his fame as theorist and teacher increased steadily, and by 1817 most of his pupils became professors at the Conservatoire de Paris. The following year, Reicha himself was appointed professor of counterpoint and fugue at the Conservatoire with the support of Louis XVIII, despite opposition from its influential professor of composition and (from 1822) director Luigi Cherubini This second Paris period produced several important theoretical writings. Cours de composition musicale, published by 1818, became the standard text on composition at the Conservatoire; the Traité de mélodie of 1814, a treatise on melody, was also widely studied. Another semi-didactic work, 34 Études for piano, was published by 1817. It was also in Paris that Reicha started composing the 25 wind quintets which proved to be his most enduring works: far more conservative musically than the experimental fugues he had written in Vienna, but exploiting the skill of his virtuosi from the Opéra Comique to extend significantly the technique and musical ambitions of future players of the still evolving wind instruments. In 1818 he married Virginie Enaust, who bore him two daughters. Around this time he taught composition to the future pioneer of the modern oboe Henri Brod, and in 1819 he began teaching harmony and music theory to Louise Farrenc; after interrupting her studies for her own marriage, she completed studies at the Paris Conservatory with Reicha in