With improved education and the freedom brought by secularisation, the 17th century saw several notable authors develop the Swedish language further. Some key figures include Georg Stiernhielm (17th century), who was the first to write classical poetry in Swedish; Johan Henric Kellgren (18th century), the first to write fluent Swedish prose; Carl Michael Bellman (late 18th century), the first writer of burlesque ballads; and August Strindberg (late 19th century), a socio-realistic writer and playwright who won worldwide fame. The early 20th century continued to produce notable authors, such as Selma Lagerlöf, (Nobel laureate 1909), Verner von Heidenstam (Nobel laureate 1916) and Pär Lagerkvist (Nobel laureate 1951).