Ivan Kosnica graduated at the Faculty of Law, University of Zagreb in 2006. After that he enrolled in the postgraduate study of public law and public administration in 2007. In 2012, he successfully defended his dissertation thesis on Citizenship in the Kingdom of Croatia and Slavonia from 1848 to 1918, obtaining a doctoral degree in legal sciences. Between 2006 and 2012 he worked at the Faculty of Law, University of Zagreb as an assistant at the Department of Croatian History of Law and State. After defending his dissertation, he was employed at the position of a senior assistant. In 2014, he was elected as a scientific associate, and in 2015 to the scientific-teaching title of an assistant professor and to the position of an assistant professor. In February 2020, he was elected to the title of a senior research associate, and in December 2020, to the scientific-teaching title of an associate professor and to the position of an associate professor. He holds the course Croatian legal history in the European context, seminars on that subject, as well as the courses Development of Citizenship and Summer School in Croatian Legal History. He is an associate on the courses Citizens’ Rights – Traditional Determinants and History of Croatian Administration. As part of the Croatian Legal History Summer School course, he participates in the preparation of students and in the organisation of the student conference, which is held alternately in Zagreb and Budapest.

He is the author of about 30 scientific papers in which he dealt with issues in the field of citizenship, nationality, citizens’ rights, states of emergency, Mažuranić’s reforms, government organization, concessions, etc. He has participated in more than thirty scientific conferences abroad and in Croatia. As an invited lecturer, he has participated in scientific conferences in Vienna, Szeged, Ljubljana, Frankfurt am Main and Budapest. In 2017, he taught at the doctoral school of the Faculty of Law of the University of Szeged as part of Erasmus. In 2019, he taught at the Jagiellonian University in Krakow also as part of Erasmus. He is a member of the editorial board of the Journal on European History of Law. He was a member of the editorial board of the Zagreb Law Review in the period from December 2017 to November 2021. Since January 2019 he has been acting as a network chair within the European Social Science History Conference (Politics, Citizenship and Nations network). In this capacity, he participated in the organisation of the European Social Science History Conference in 2021 (online event) and in the organisation of the European Social Science History Conference in 2023 at the University of Gothenburg. He organised a scientific gathering on occasion of the 30th anniversary of the entry into force of the Law on Croatian Citizenship together with his colleague Frane Staničić on 8 October 2021. In May 2021, he participated in a round table as part of the Kliofest history festival. He is the chairman of the Committee for Preservation of Tradition of the Faculty of Law, University of Zagreb. During the academic year 2022/2023 he participated in the working group for the drafting of the Code of Ethics of the Faculty of Law, University of Zagreb. He speaks English fluently and uses German in his research.