Horst was born in the city of Grijzestad to artist Simon Horst and a cabaret dancer, Elsa. Around 1930, he studied law at the Royal University of Koningstad. There he began acting and was noticed by a Broadway producer. He spent much of the 1930's in America. In 1935 the theater he worked at went broke and he moved across the country looking for work. In 1937, he came to Lovia and had a little more luck. He worked as a lawyer in Noble City. In 1945, he began to work for Transbaum Films, starring in such movies as The Grey City and The Count of Sylvania . He married a Swedish model in 1946. In 1953, he had the small Drenthe Castle demolished and rebuilt in Ferguson Beach Village, which served as his Lovian home. Horst returned to Brunant in 1967 after the end of his career. He would later alternate between living in Brunant and Lovia, until his death.