Schiele joined the Vienna Academy of Art in 1906 but left in 1909 because his teacher disapproved of his paintings, which were influenced by the art nouveau artist Gustav Klimt. By 1910 he had evolved a mature style of his own, which was expressionist in character although Schiele never identified himself with the expressionist movement. During the next eight years he produced the oils, watercolours, and drawings – mostly portraits – upon which his reputation rests. Distorted, neurotic, and unappealing, the portrait figures nevertheless reveal the artist's great sensitivity and masterly draughtsmanship. The element of eroticism in some of them resulted in Schiele spending a month in prison in 1911. In 1913 he was drafted into the army, four days after his wedding; he spent part of World War I as a war artist. In 1918 at the exhibition of the Vienna Secession his pictures received international acclaim, but his death the same year of Spanish influenza deprived the world of a highly original talent.