Born Dec. 12, 1892, in Gorizia. Yugoslav historian and medievalist, full member of the Slovenian Academy of Sciences and Arts (1938). The son of F. Kos.
Kos was educated in Vienna and Paris. From 1924 to 1926 he taught in the universities of Belgrade and Zagreb. In 1926 he became a professor at the University of Ljubljana. His basic works deal with the history of Slovenia from the seventh to the 15th centuries. He has also given a great deal of attention to the study and publication of historical sources.