International law and its science, 1789-1914

Project leader: Prof. em. Dr. Dr. h.c. mult. Michael Stolleis

The project examined paradigmatic changes in legal structures in international relations in the 19th and early 20th centuries. Both international law practice and international law scholarship were of interest. The aim was to understand international law as a separate type of normative order in an interdisciplinary research context and to analyze its historical structural features: What goals and values constituted international law in the 19th century? Who were the actors and what legal instruments did they use? In what form did global norms and orders become universalized?

As a result, it emerged that international structures underwent a remarkable development during the research period: Between the end of the Ancien Régime and the outbreak of the First World War, international law developed from a law of coexistence to a law of cooperation. New international regimes were established to regulate diverse political, social and economic interests, and relations between states became more legalized; at the same time, however, there were also areas in which legal avoidance dominated (sovereign debt; right of intervention). Principles that are still valid today, such as the fundamental rights of states or the international community, emerged. Intergovernmental organizations began to shape international relations. In the process, both a separation of international law from morality and the adoption of fields of activity that signify a “moralization” of law can be observed.

This change in the practice of international law was accompanied, promoted and reflected by numerous scholars of international law. In addition to individual authors, of whom Georg Friedrich von Martens, Theodor Schmalz, Julius Schmelzing, Friedrich Saalfeld, Carl Baron Kaltenborn von Stachau, Robert von Mohl, Henry Wheaton, August Wilhelm Heffter, August von Bulmerincq, Carl Bergbohm, Johann Caspar Bluntschli, Leopold Neumann, James Lorimer, William Edward Hall, Fedor Fedorowitsch von Martens, Carlos Calvo, Henry Bonfils, Franz von Liszt, John Westlake, Frantz Despagnet and Lassa Oppenheim should be mentioned, the founding of the Institut de Droit International in particular testifies to the importance and influence of science on the newly invented system of international law.

A particular concern of the project group’s research was the analysis of the academic accompaniment of the juridification process by the authors of international law and political science: they commented on the institutionalizations that took place in the course of the 19th century and accompanied the processes of negotiating an international normative order in their contemporary interpretations and historical narratives. In doing so, they often developed affirmative, rarely alternative concepts of order. The question of universalist claims to justice in a world order, whether based on the morality of nations or the demand for equal treaties through to the resolution of state bankruptcies, which took place in and through international law, emerged as an aspect of this, as did the emergence and establishment of general legal principles of international law, taking into account contemporary academic discourse.

The results are available in the form of several monographs and anthologies. The most important of these include
Nuzzo, Luigi/Vec, Miloš (eds.) (2012): Constructing International law – The Birth of a Discipline (Studien zur europäischen Rechtsgeschichte 273), Frankfurt/M.: V. Klostermann, XVI, 545 pp.
Heimbeck, Lea (2013): The resolution of state bankruptcies in international law. Legalization and legal avoidance between 1824 and 1907 (Studies in the History of International Law), Baden-Baden: Nomos.
Stefan Kroll (2012): Norm genesis through re-interpretation. China and European international law in the 19th and 20th centuries (Studies in the History of International Law 25), Baden-Baden: Nomos.
Klump, Rainer/ Vec, Miloš (eds.) (2012):International Law and the World Economy in the 19th Century (Studies in the History of International Law 26), Baden-Baden: Nomos, VII, 271 pp.
Lovric-Pernak, Kristina (2013): Morale internationale and humanité in international law of the late 19th century. Meaning and function in state practice and science (Studies in the History of International Law 30), Baden-Baden: Nomos, 200 pp.

The most important events in the research project include
“Storia teoria e diritto internazionale. La costruzione di una disciplina”, International Conference, Lecce (Italy) May 20-22, 2009, “Völkerrecht und Weltwirtschaft im 19. Jahrhundert. Die Internationalisierung der Ökonomie aus völkerrechts- und wirtschafts(theorie-)geschichtlicher Perspektive”, Workshop, 3-4 September 2009 in Frankfurt am Main, Max Planck Institute for European Legal History and “The Emergence and Transformation of Foreign Policy.” International Conference, Johns Hopkins University, Bologna, June 10-12, 2011.

Further information at: https://www.rg.mpg.de/forschung/voelkerrechtsgeschichte

News from the research center

Event
18.04.2026 | Frankfurt am Main

Das Prinzip Donald Trump und die Verrohung der Welt

Panel Discussion, Lecture

Ein neuer Politikstil macht international Karriere. Er ist gekennzeichnet von Vulgarität, Verrohung und erklärter Rechtsfeindschaft. Machtinteressen werden nicht mehr juristisch bemäntelt. Stattdessen wird das angebliche Recht des Stärkeren zur Staatsdoktrin gemacht – innenpolitisch wie außenpolitisch. Treibende Kraft hinter dieser Verrohung der politischen Sitten ist ein US-Präsident, der nicht nur die amerikanische Gesellschaft und Kultur, sondern auch die globale Ordnung nach seinen Vorstellungen und Interessen umgestaltet. Die Römerberggespräche wollen diesen Politikstil verstehen.

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Event
29.04.2026 | Frankfurt am Main

Kulturindustrie heute?

Panel Discussion

Das Gespräch „Kulturindustrie heute?“ widmet sich der Aktualität und Tragfähigkeit eines zentralen Begriffs der Kritischen Theorie. Die Filmwissenschaftlerin Gertrud Koch diskutiert im Rahmen der Gesprächsreihe "Frankfurter Schule" mit dem Filmkritiker Bert Rebhandl die gegenwärtigen Formen kultureller Produktion und Verbreitung vor dem Hintergrund von Digitalisierung, Plattformen und globalen Medienmärkten.

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Event
20.03.2026 | Frankfurt am Main

40 Jahre Schengen-Raum

Colloquium

Der 1984 geschlossene Schengen-Vertrag schuf einen heute 29 Staaten umfassenden Raum ohne Binnengrenzen, doch Migration über die Außengrenzen führte zuletzt zur Wiedereinführung von Kontrollen, auch durch die Bundesregierung ab 8. Mai 2025. Das Walter Hallstein-Kolloquium diskutiert die rechtliche Zulässigkeit, wirtschaftliche Folgen insbesondere für Arbeitsmigration und Arbeitsmarkt sowie die Zukunft des Schengen-Raums.

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News
12.02.2026

Satanist politics and the decline of reason in liberal democracies

For the last time in the winter semester 2025/26, the Research Center hosted the lecture series "Am Scheidepunkt. On the crisis of democracy". At the end, philosopher Michael Rosen from Harvard University presented his concept of "satanic politics" as a variant of the political interpretation of the world.

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News
09.02.2026

On the topicality of the concept of violence based on Camus and Derrida

Prof. Dr. Christine Abbt from the University of St. Gallen gave a lecture on democracies and the concept of violence as part of the lecture series "At the crossroads? On the crisis of democracy", she gave a lecture on democracies and the concept of violence. Under the title "Defending democracies. On the topicality of the concept of violence in Camus and Derrida", the philosopher discussed forms of violence and revolt and categorized them with regard to a democratic setting.

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Publication
04.02.2026 | Journal article

New Perspectives on Trust in International Conflicts

Wille, Tobias; Simon, Hendrik; Daase, Christopher; Deitelhoff, Nicole; Wheeler, Nicholas J.; Holmes, Marcus; Rathbun, Brian C.; Acharya, Amitav; Mitzen, Jennifer (2026): „New Perspectives on Trust in International Conflicts“. In: International Studies Review 28 (1), viaf027.

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News
02.02.2026

States competing for people - David Owen on civil geopolitics

As part of the lecture series "At the Crossroads - The Future of Democracy", David Owen from the University of Southampton presented his concept of civil geopolitics.

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News
20.01.2026

Christine Hentschel on reorientation in catastrophic times

As part of the lecture series "At the crossroads? On the crisis of democracy", the sociologist spoke about living in and dealing with catastrophic times. Against the backdrop of the destruction of living conditions, wars, permanent crises and threats to democracy, Hentschel addressed the infiltration of the catastrophic into everyday social life and a changing activist and literary approach to the future.

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Publication
08.01.2026 | Journal article

Gender Differences in Financial Advice

Bucher-Koenen, Tabea; Hackethal, Andreas; Koenen, Johannes; Laudenbach, Christine (2025): „Gender Differences in Financial Advice“. In: American Economic Review, 115 (12), pp. 4218–4252.

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