After the seven symphonies and the violin concerto, Sibelius's thirteen symphonic poems are his most important works for orchestra and, along with the tone poems of Richard Strauss, represent some of the most important contributions to the genre since Franz Liszt. As a group, the symphonic poems span the entirety of Sibelius's artistic career (the first was composed in 1892, while the last appeared in 1925), display the composer's fascination with nature and Finnish mythology (particularly the "Kalevala"), and provide a comprehensive portrait of his stylistic maturation over time.