Rodin was the most important personality in the sculpture of the end of the 19th century. As the last great classical sculptor he was also the founder of modern sculpture. He took a completely new direction, introducing an Impressionist liveliness in the form of a play of light and shadow on his figures. He also succeeded in expressing the essence of human emotions by means of their bodies. This was quite an innovation at the time. His art also had a revolutionary influence on the future development of sculpture in the 20th century. Rodin discovered his interest in sculpture during a three-year training at the Petite Ecole, a training school for craftsmen, which he began in 1854. He applied at the Grande Ecole, but failed three times to pass the entrance exam. As a classical education was not possible, he began working as a decorator in order to survive as an independent artist. His public success as a sculptor only came towards the end of the 1880s, when an exhibition of 36 works in 1889 finally had the deserved positive response. Before then, until the 1870s, Rodin worked as an architectural sculptor in Brussels and later at the manufacture in Sèvres. The following decade brought state commissions for the Hell's Gate, the Burgers of Calais, the monument to Victor Hugo and the large marble version of the sculpture 'The Kiss'. In 1883 Rodin met Camille Claudel, who became his assistant, his model and his concubine for the next 15 years. He continued his relationship with Rose Beuret, whom he had met in 1864 and who stayed his partner until their marriage in 1917. The 1890s began with the commission for a monument to Balzac. While working on this work Rodin developed a sculpture which was supposed to reflect the poet's inner spiritual life. Rilke became Rodin's secretary in 1905, but was dismissed again in 1906. 'The Thinker' was erected in the same year in front of the Pantheon. The most important source of Rodin's art theory, 'L'Art' was published in 1911. The Musée Rodin was constituted at the Hôtel Biron in 1916, one year before Rodin's death, after the artist donated his works to the state.