Related Information for Jean Sibelius Jean Sibelius (1865–1957) was a Finnish composer. Sibelius was one of the most popular composers of the late nineteenth and early twentieth centuries.Sibelius was born on 8th December 1865 into a Swedish-speaking family in Hämeenlinna in the Russian Grand Duchy of Finland. He was given the name Johan Julius Christian Sibelius, and known as Janne to his family, but during his student years he started using a French form of the name, Jean.His most popular compositions include Finlandia,.. read more