The Section of International Law mourns the loss of its long-time department head, emeritus Prof. Dr. Karl Zemanek, who passed away on 24 February 2025. Prof. Zemanek was one of the pillars of the Vienna School of International Law, which has shaped numerous generations of international lawyers.
Karl Zemanek was born in Vienna on 18 November 1929. He studied at the University of Vienna, in Oxford, Paris and Saarbrücken before completing his doctorate at his home university in 1952. In 1957, he was awarded the venia legendi for his habilitation thesis on the treaty law of international organizations. From 1964 to 1996, he was a full professor of international law at the University of Vienna and continued teaching for many years as an emeritus professor in the postgraduate LL.M. program in international legal studies at the University of Vienna.
In addition to his teaching obligations, he served in the role of legal advisor (jurisconsult) to the Foreign Ministry, a position he held from 1967 to 2003 and in which he often represented Austria in the Sixth Committee of the United Nations General Assembly in New York. In addition, he chaired codification conferences on State Succession in Treaties and on the Law of Treaties of International Organizations in 1977/78 and 1986.
Prof. Zemanek was active in numerous academic associations. His activities on the Board and the Council of the German Society for International Law, his membership in the Institut de droit international and his longstanding work in the International Law Association, where he was particularly active in the committees on State succession, landlocked states and customary international law. He also chaired the Austrian Branch of the ILA for many years.
At The Hague Academy of International Law he gave lectures on State Succession in the Context of Decolonization in 1966 and the General Course on “The Legal Foundations of the International System” in 1997.
In his teaching, Prof. Zemanek was distinguished by his special talent for distilling complicated issues and rules to their essence and for explaining complex underlying problems in an understandable way. As someone who has been firmly rooted in practice for decades, he was also able to present the political context necessary for a better understanding of the law. In this way, he made a significant contribution to the education of generations of international lawyers.
His scholarly interest, always focused on the fundamentals of the subject, was coupled with a special sensitivity to political realities. For many members of the Department/Section this made him an important contact, who always took the time to discuss problems of international law. The Department will miss him and will honour his memory.
