Born Dec. 24, 1853, near the city of škofja Loka; died Mar. 14, 1924, in Ljubljana. Slovenian historian and medievalist. Koš graduated from a university in Vienna and in 1881 received his academic degree.
Between 1880 and 1911, Kos taught in Gymnasiums in Lju bljana, Koper, and Gorizia. His scholarly publications dealt with sources of the early Middle Ages in Slovenia. In his historical works he refuted the theory of the autochthonous nature of the Slovenian population, a theory widespread among Slovenian historians of the late 19th century.