Dušan Kos has been a researcher at the Milko Kos Historical Institute of ZRC SAZU since 1987. Since graduating in 1987 and receiving his PhD in 1993 from the Faculty of Arts in Ljubljana, he has researched medieval and early modern Slovenian history, focusing on the publication of historical written sources (charters, city statutes, urbaria, diaries) and especially on the history of everyday life as well as social and cultural history. He is the author of seventy original scientific articles and twenty-seven sole‑authored monographs and is first co‑author of two further monographs.
Dušan Kos conducts intensive research on the medieval and early modern history of the Slovenian lands, primarily in the fields of social and cultural history, the history of mentalities, and everyday life. He also works in the diplomatics of medieval charters and publishes historical written sources (charters, city statutes, urbaria, diaries). He is interested in the processes and phenomena that shaped Slovenian social structures in their earlier phases and laid the foundations for modern structures.
From the outset he has participated in the research programmes and projects carried out at ZRC SAZU. Over the past three decades he has led five projects funded by the Ministry of Higher Education, Science and Technology of the Republic of Slovenia and by the Slovenian Research and Innovation Agency, fostering collaboration with colleagues from various research institutions in Slovenia and abroad. Since 1992 he has also been a member of the Institute for Austrian Historical Research in Vienna (Institut für Österreichische Geschichtsforschung). His further research aims focus on an in‑depth analysis of the everyday life of all social strata in the earlier periods of Slovenian history.
- Posest ljubljanske komende nemškega viteškega reda, Dušan Kos. 1984.
- Gospodarske in socialne razmere na imenju Golnik (Gallenfels) sredi 18. stoletja, Dušan Kos, Marija Perko.
- Metliški grad po inventarju leta 1723, Dušan Kos. 1986.
- Bela krajina v poznem srednjem veku, Dušan Kos. 1987.
- Bela krajina v poznem srednjem veku : (nadaljevanje in konec razprave), Dušan Kos. 1987.
- Gospostvo novomeškega kapitlja do srede 17. stoletja, Dušan Kos
- Zgodovinski razvoj naselij goriškega kota, Dušan Kos. 1990.
- Lastniki, posestniki in prebivalci grajskih poslopij na Celjskem do začetka 15. stoletja, Dušan Kos. 1993.
- Plemiška darovanja cerkvenim ustanovam : (s posebnim ozirom na 14. stoletje), Dušan Kos. 1993.
- Dediščine, dedno pravo in plemstvo na Kranjskem in slovenskem Štajerskem v 13.in 14. stoletju, Dušan Kos. 1994.
- Življenje, kot ga je pisala dota : vloga poročnih prejemkov v življenju kranjskega in slovenještajerskega plemstva v 14. stoletju, Dušan Kos. 1994.
- Pamet pod šlemom, zvestoba denarju : plemiški karierizem v luči uradovanja, služenja in vojskovanja v poznem srednjem veku, Dušan Kos. 1995.
- Gorenjski samostani in plemstvo do začetka 15. stoletja, Dušan Kos. 1995.
- William's last temptation, Dušan Kos. 1995.
- V primežu pobožnosti, karierizma in (samo)preskrbe (od konca 13. do začetka 15. stoletja), Dušan Kos. 1996.
- Gradovi, dvorci in plemstvo med Krko in Gorjanci do konca srednjega veka, Dušan Kos, Tadej Bratè, Marinka Dražumerič, Andrej Hudoklin.
- Zur Problematik des öffentlichen Notariats in Krain im Mittelalter, Dušan Kos.
- Pot na Avalon, Dušan Kos. 1997.
- Vitez in ugrabljenka : nasilnik in njegova žrtev?, Dušan Kos. 2002.
- Das Turnierbuch des Caspar von Lamberg : (Karriere eines Turnierhelden von Krain), Dušan Kos. 002).
- Grb in mit : primer psevdokraljevskega izročila o gospodih Svibenskih (12.-19. stoletje), Dušan Kos. 2002.
- Listinska praksa v provinci : primer Kranjske v letih 1150-1300, Dušan Kos. 2003.
- Civilne žrtve tržaškega zraka. Je bila melanholija v starem režimu slabost ali zločin?, Dušan Kos. 2004.
- Trdota kot vrednota : prispevek k historični antropologiji impotence v predmeščanski dobi = Hardness as a worth : contribution to the historical anthropology of impotence in the pre-bourgeois age, Dušan Kos. 2004.
- Franc Henrik Raigersfeld: Dnevniki 1697–1759. Dušan Kos, 2024.
- 1993–2003 University of Ljubljana, Faculty of Arts, Department of History: course Auxiliary Historical Sciences.
- 1993–2003 University of Ljubljana, Faculty of Arts, Department of Art History: courses Latin Palaeography and Heraldry.
- 2005–2013 University of Primorska, Faculty of Humanities: course Auxiliary Historical Sciences.
- KLIO Award for the best historiographical book in Slovenia, published in 2017–2018.