How do the pathways of Dutch converts to Islam involved in jihadist movements differ from those of Dutch converts who are not, in terms of their life prior to Islam, their conversion experience and the form of involvement with the Islamic community after conversion?

By looking at what is different, researchers often discover the special, the unusual. And that has already brought a wealth of highlights – also in Leiden.

The widely used pesticide thiacloprid can cause a large-scale decline in freshwater insects. This was discovered by researchers from the Living Lab in Leiden. For three months they counted the flying insects in the 36 ditches of the lab. Their research appeared in PNAS.

Since 2012, thousands of individuals have traveled from Western countries to join jihadist groups in Syria and Iraq. While much has been written about these individuals, only sparse attention has been paid to the social environment of these jihadist travelers and, more specific, the role of family members…

Joseph Callingham from the Leiden Observatory receives the Louise Webster Prize for outstanding post-doctoral research. The prize is awarded by the Astronomical Society of Australia for Callingham’s search for the most extreme object in the Universe.

How to minimalize the chance of recidivism for extremist prisoners.

Physical chemist Rik Mom developed a revolutionary way to investigate catalysts in action in detail. For this work he received the distinction cum laude during his PhD defence on 29 June.

A professor from Leiden University has subjected various colleagues to intimidating and unacceptable behaviour for a longer period. These are the findings of an investigation carried out by the University’s independent Complaints Committee for Unacceptable Behaviour at the request of the Executive Board…

Interdisciplinarity is more than a buzzword in academia. It’s essential for tackling today’s biggest challenges. But what does it look like in practice? How can PhDs learn the skills needed to work across disciplines, and how can supervisors master the art of guiding them?

This book underscores the interplay between religion and politics (local and global) in the production, escalation, management, mitigation, and resolution of conflict.

At our regular panel discussions we bring together scholars and other experts to discuss a current topic that captures the interest of the general public as well as academics.

Nikki Sterkenburg, external PhD candidate at the Institute of Security and Global Affairs in The Hague, was interviewed by the NOS programme Nieuws & Co about the meeting of Thierry Baudet with Alt-Right movement Jared Taylor. 'If Baudet would have wished to stay aloof of this movement, he shouldn’t…

Understanding the evolving landscape of extremism in the 21st century.

Vasiliki Kosta gave a presentation during the session ‘Building Academic Freedom’ taking place at Leiden University on 25 November 2025.

The course is taught by experts from Leiden University’s Institute of Security and Global Affairs, alongside leading practitioners. Their expertise spans international relations, security policy and counterterrorism, bridging academic insight with real-world experience.

The METIS instrument that’s being built for ESO's future Extremely Large Telescope (ELT) in Northern Chile under the leadership of the Dutch Research School for Astronomy (NOVA) has reached an important milestone: the preliminary design has been approved.

Leiden scientists will be working on the development of a camera for the European Extremely Large Telescope that is currently under construction. On 28 September the Netherlands Research School for Astronomy signed an agreement with the European Southern Observatory.

The funerary textile tradition from the Osmore Valley, South Peru, and its social-political implications (2005)

After this course

The Terrorism and Political Violence (TPV) research group focuses on understanding and addressing one of today’s most pressing security challenges: terrorism. Drawing from their academic expertise, the group offers a wide range of educational programmes designed for students, professionals, and a global…

The Dutch Department of Justice will give imprisoned terrorists the opportunity to earn money. This should have an positive effect on the resocialisation of detainees.

In the track Terrorism and Political Violence you will be familiarised with the academic debate regarding these contested concepts.

This thesis is largely an experimental study on the formation of solid-state simple and complex organic molecules in the H2O-rich and CO-rich ice phases of dense interstellar clouds and dark cores.

From 2012 onwards the primary scholarly and media focus in regard to foreign fighters has been on the large number of Westerners joining jihadist groups in Syria and Iraq. Yet, much less attention has been paid to another conflict in the ring around Europe that attracted foreign fighters: the Russo-Ukrainian…

During post-embryonic development into adults, animals face an environment that fluctuates constantly. For example, in nutrient availability, temperature, and osmolarity (e.g., salt concentration).

In this article, Gerrit Dijkstra and Jos Raadschelders from the Institute of Public Administration, focus on Russia’s role in Bosnia and raise some important questions.

Promotor: Prof.dr. M.K. Richardson, Co-Promotor: F. Witte

In the last two decades, there have been heated public and scholarly debates in France, the United Kingdom, and the Netherlands on the violent end of empire. Nevertheless, the broader comparative investigations into colonial counterinsurgency tend to leave atrocities such as torture, execution, and…

In the Master's programme Crisis and Security Management, specialisation Terrorism and Political Violence, we focus on the academic body of knowledge on different form of protests, contention, resistance and violence. We explore and explain the emergence of radical and extremist movement.

Are you thinking about studying Crisis and Security Management: Terrorism and Political Violence ? Learn more and watch the videos.

This course is designed for professionals working in or with the security domain.

These three repors are part of a research project that assesses how military interventions can best prepare the ground for an effective long-term counter-terrorism policy. Three different cases have been studied, and they have each provided the input for the policy relevant recommendations that are…

This book aims to unravel some of the mysteries surrounding this exceptional group of larger-than-life Bronze Age blades.

When and how does social anxiety develop? How can it go astray in some adolescents? How can we help troubled young people to attend school regularly and return to a normal developmental pathway?

Cutting-edge technological innovation for businesses and consumers, enabled by top-tier research on space and the quantum world.

Our courses are aimed at higher educated professionals, starters, experienced professionals and managers. You can choose from day-long Masterclasses, multi-day courses and an intensive one-year program. Our offer exists off on the themes below.

What the Sex Lives of Bugs, Birds, and Beasts Tell Us About Evolution, Biodiversity, and Ourselves, Menno Schilthuizen reports from the front lines of evolutionary biology, on a quest to make sense of the origins, workings and evolution of our and other species’ reproductive selves.

Promotores: Prof.dr. F.P. Israel, Prof.dr. P.P. van der Werf

From Incident to Precedent

Promotor: E. Bouwman Co-Promotor: S. Bonnet

In dit onderzoek worden orde isomorfismen en orde antimorfisme bestudeerd in het algemene kader van partieel geordende vector ruimten.

All players on the world stage operate strategically in order to safeguard their interests. Political scientists at Leiden University cast light on this volatile interplay of forces. Their research helps voters, NGOs, governments and international organizations make smart choices in this complex and…

Astronomers want to understand the Universe, from the Big Bang to the present day, and what the future will hold. In Leiden they focus on two key questions: ‘How did stars and planets originate’ and ‘How were galaxies and black holes formed in the young Universe?’ A new generation of telescopes – just…

Seagrass is a marine flowering plant with special adaptations to coastal and marine environments, playing a crucial role in providing a wide range of ecosystem services.

Sub-Saharan Africa has seen a significant rise in terrorist acts and radicalized youth since the appearance of Boko Haram in 2009 and the fall of Libya in 2012. This book investigates the deeper layers of radicalization in Sub-Saharan Africa, which is situated in a larger global tendency.

The parabolic Anderson model (PAM), which is the Cauchy problem for the heat equation with random potential. The PAM is a mathematical model that describes how mass (i.e. matter or energy) flows in a medium in the presence of a field of sources and sinks.