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Frits Kalshoven


Many students know Frits Kalshoven as the author of the book Constraints on the Waging of War, which is for many their first acquaintance with international humanitarian law.

Frits Kalshoven is Professor Emeritus of Public International Law and International Humanitarian Law at Leiden University. He is one of the world's most renowned experts on international humanitarian law.

Academic life

Prof. Kalshoven was born in 1924 in Den Haag. He began his career as an officer in the Royal Netherlands Navy (1945-1967). During this time he studied law at the Universiteit Leiden, where he graduated in 1958. He subsequently went on teaching public international law, the law of naval warfare and Dutch criminal and military law at the Dutch Royal Naval Academy (1958-1967). Four years later he received his doctorate in Leiden on the subject of Belligerent Reprisals. ​

Professor Kalshoven went on to work as professor of public international law at the Universiteit Leiden from 1967 until 1985. From 1975 on he also held the position of Extraordinary Professor of international humanitarian law at the Universiteit Leiden (until 1989) and was isiting Professor of international humanitarian law at the Rijksuniversiteit Groningen (1999 - 2003).

Frits Kalshoven and the Red Cross

Besides academic work, professor Kalshoven has been an advisor to the board of the ​Netherlands Red Cross (1971-1993), in which capacity he represented the Netherlands Red Cross at numerous meetings of the Red Cross/Red Crescent Movement. Prof. Kalshoven took part in the diplomatic conference on "Reaffirmation and Development of International Humanitarian Law Applicable in Armed Conflicts" which negotiated the 1977 Protocols to the Geneva Conventions of 1949, and the conferences that drafted and negotiated the 1981 Conventional Weapons Convention.

In 2002, Prof. Kalshoven was awarded the Henry Dunant Medal, the highest distinction of the International Red Cross and Red Crescent Movement. On this occasion the ICRC said that he "is credited as one of the driving forces behind the development of the Protocols additional to the Geneva Conventions. An eloquent and outspoken orator, Professor Kalshoven has untiringly defended the relevance of [international humanitarian law]."


Prof. Kalshoven is the author of numerous publications on the laws of armed conflict. Besides Constraints on the Waging of War: An Introduction to International Humanitarian Law (3rd edition, with Liesbeth Zegveld, Geneva: ICRC, 2001), these include Belligerent Reprisals (Leiden: Sijthoff, 1971; 2nd edition, Leiden: Martinus Nijhoff, 2007). His collected essays appeared in 2007 as Reflections on the Law of War: Collected Essays (Leiden: Martinus Nijhoff, 2007).
During the first edition of the national competition on IHL held in the Netherlands, Frits Kalshoven was part of the jury that assessed the performance of the first participants. It was a great pleasure for the organisers that Prof. Kalshoven accepted that his name would be given to this competition. We are happy that in this way we can honour a person who has played such an important role for this field of law in the Netherlands and indeed the rest of the world.