How do commissions of inquiry operating in conflict situations utilize international law, and how can inquiry findings be utilized by other bodies belonging to the international legal community?

This PhD dissertation examines international responsibility for the crime of aggression from a public international law perspective. Under customary international law, as well as the amendments to the Rome Statute of the International Criminal Court adopted in the Review Conference in Kampala in 2010,…

Ending the United Kingdom’s (UK) forty-seven year European Union (EU) membership has fundamentally transformed its relationship with the EU. After years of tumultuous negotiations, international law now once again governs the UK’s relationship with the EU. This has resulted in a sophisticated body of…

Using the League of Nations’ responses to early crises as an explorative historical case study, Political Scientist Gisela Hirschmann investigates how international organisations perceive and respond to existential threats.

On 18 April, Alexandre Tavadian defended the thesis 'The International Civil Service: Redefining Its Independence'. The doctoral research was supervised by Niels Blokker and Brian McGarry.

This book offers a comprehensive analysis of the international law applicable to cyber operations, including a systematic examination of attribution, lawfulness and remedies. It demonstrates the importance of countermeasures as a form of remedies and also shows the limits of international law, highlighting…

Are you considering starting a master’s programme in Psychology at Leiden University and are you planning on pursuing a career outside of the Netherlands? If so, then before your start your studies, make sure to check if your preferred country has special requirements to work as a psychologist, in…

Are you considering a career outside of the Netherlands after following a Dutch bachelor ánd master programme? If so, then before your start your studies, make sure to check if your preferred country has special requirements to work as a psychologist, in addition to the Dutch title Master of Science…

Are you considering starting a master’s programme in Psychology at Leiden University and are you planning on pursuing a career outside of the Netherlands? If so, then before your start your studies, make sure to check if your preferred country has special requirements to work as a psychologist, in…

Are you considering starting a master’s programme in Psychology at Leiden University and are you planning on pursuing a career outside of the Netherlands? If so, then before your start your studies, make sure to check if your preferred country has special requirements to work as a psychologist, in…

Are you considering starting a master’s programme in Psychology at Leiden University and are you planning on pursuing a career outside of the Netherlands? If so, then before your start your studies, make sure to check if your preferred country has special requirements to work as a psychologist, in…

Are you considering starting a master’s programme in Psychology at Leiden University and are you planning on pursuing a career outside of the Netherlands? If so, then before your start your studies, make sure to check if your preferred country has special requirements to work as a psychologist, in…

Are you considering starting a master’s programme in Psychology at Leiden University and are you planning on pursuing a career in health care outside of the Netherlands? If so, then before your start your studies, make sure to check if your preferred country has special requirements to work as a psychologist,…

Between 11 and 13 September 2025, the ESIL Annual Conference took place in Berlin, Germany. This year's conference unfolded on the theme 'Reconstructing International Law', attracting an unprecedented number of legal scholars from all over the world.

How should the international community of states respond to genocide, war crimes and crimes against humanity? How can the perpetrators of international crimes be brought to justice? How can international crimes be prevented? How can the international community of states promote international consensus…

On the 12th of May, Rita Barrera Virhuez-Eloranta successfully defended a doctoral thesis and graduated. The Leiden University Centre for Linguistics congratulates Rita Barrera Virhuez-Eloranta on this achievement.

The Private International Law Department provides academic education and performs research in the field of private international law.

The Service Centre International Staff provides advice and different services to all international employees and guest researchers pursuing their academic careers in Leiden.

Our mission is to advance the understanding of mental health of individuals with a history of stress and/or trauma through rigorous interdisciplinary research, integrating insights from clinical psychology, neurobiology, and social sciences. We are committed to translating our findings into innovative…

By choosing Leiden University, you’ll be choosing to broaden your personal and academic horizons. You’ll be in excellent company too because you’ll be part of an inspiring community of students, lecturers and professors from all over the world. Founded in 1575, ours is the oldest university in the N…

Taking the changing landscape of international cyber security and cyber conflict as a point of departure, The Hague Program on International Cyber Security focuses on the various modes of governance that states and other actors can bring into play to deal with and shape the strategic changes and challenges…

This article offers an inaugural assessment of how silences implicate international law-making in cyberspace through descriptive and normative lenses.

Are UN sanctions regimes in need of further formalization in terms of substantive design, procedural architecture and with a view to regulating and governing the interplay with other regimes?

If you are from abroad and you want to work at Leiden University, there is quite a lot to arrange.

This edited volume explores how artificial intelligence (AI) is transforming international conflict in cyberspace.

The International Labour Organisation (ILO) was established in 1919 based on the premise that social justice is a condition for lasting peace. On February 2019 the ILO celebrated its 100th anniversary with an international symposium to consider the future of the ILO.

Four famous alumni introduce their favourite films at Leiden International Film Festival

2025

Study information, Online Experience

The International Arbitration Training Course, offered by Leiden Law School in cooperation with the Permanent Court of Arbitration, focuses on the theory and practice of international arbitration as a distinct field of the law and field of legal practice. The announcement for the next edition is set…