As a historian he wrote a two-volumed work in German "Versuch einer Geschichte von Krain und der übrigen südlichen Slaven Oesterreichs" (An Essay on the History of Carniola and Other Austrian South Slavs). The first volume was published in 1788 and describes the proto-Slavic era. The second, titled "Versuch einer Geschichte von Krain und den übrigen Ländern der südlichen Slaven Oesterreichs" (An Essay on the History of Carniola and Other Lands of the Austrian South Slavs) was published in 1791. It deals with the age of migrations, the Slavic settlement in the Eastern Alps and later political development of the Slovene people, starting from Samo realm and Carantania.