Fredrik Pacius (Finnish pronunciation: [ˈfreːdrik ˈpɑːsiʉs], Finland Swedish: [ˈfreːdrik ˈpɑːsiʉs] ⓘ); in German and in Estonian Friedrich Pacius; 19 March 1809 – 8 January 1891)[1] was a German-Finnish composer and conductor who lived most of his life in Finland.
In Helsinki he founded a musical society, the student choir Akademiska Sångföreningen and an orchestra.
In 1848, Pacius wrote the music to the poem "Vårt land" by Johan Ludvig Runeberg, which was to become commonly accepted as Finland's national anthem.
In 1852, he composed Kung Karls jakt (English: King Charles' Hunt; Finnish: Kaarle-kuninkaan metsästys), which was the first Finnish opera, with a libretto in the style of Romantic nationalism, like the national anthem designed to convince Finland's grand duke (i.e. the Russian Emperor Nicholas I) of the total loyalty of his subjects in Finland.
The libretto was written by the author and historian Zacharias Topelius in close collaboration with Pacius.