Leonhard den Hertog

Dear visitor,

Welcome to my personal webpage! 

I invite anyone with questions or suggestions on my work and ideas for future cooperation to contact me at: 


Hope to hear from you,


Key Interests
  • The Rule of Law
  • EU external relations law; especially the role of constitutional principles
  • EU Justice and Home Affairs policies; especially external dimension of migration policy/border policy
  • EU development cooperation; especially EU's role in Ethiopia
My Bio

I obtained my LLM degree in 2010 after completing the Legal Research Master at the University of Utrecht. During my LLM studies I carried out research projects on inter alia Frontex (EU Border Agency) joint operations in light of refugee and human rights law, the reception of EU law in the Member States’ legal order and the principle of loyal cooperation within CFSP. During those years, I also worked as research assistant for professors at the University of Utrecht and of Amsterdam on European constitutional law and worked for an Amsterdam-based law firm as paralegal on European law. Furthermore I interned at a civil society project (Cotonou Task Force) on EU development policy in Addis Ababa (Ethiopia) funded by the local EC Delegation.

Since October 2010 I am a PhD student within the EXACT programme. My joint host universities within this network are the University of Cologne and of Edinburgh. From March to October 2011 I was based at the Centre for European Policy Studies (CEPS) in Brussels where I worked within the Justice and Home Affairs (JHA) unit; there I dealt mainly with Frontex and EU border policy. Subsequently, I worked 5 months at the Hungarian Academy of Sciences in Budapest, dealing mostly with EU's international responsibility and the Rule of Law. Currently I am based at the University of Cologne's Jean Monnet Chair, combined with regular shorter stays at the University of Edinburgh. 

Please do not hesitate to contact me if you have similar research interests; I am looking forward to an exchange of ideas on these matters.

EXACT stages
October 2010 – February 2011 University of Cologne
March 2011 – October 2011 The Centre for European Policy Studies (CEPS), Brussels
November 2011 – March 2012 Hungarian Academy of Sciences (HAS), Budapest
April 2012 – September 2013 University of Cologne / Edinburgh
PhD research project

Title of research project: 'EU's external dimension of migration policy: organisational

dynamics and constitutional principles' 


Supervisors: Prof. Wolfgang Wessels (University of Cologne) & Prof. Christina Boswell

(University of Edinburgh)


Over the past decade the EU and its Member States have given increasing priority to the development of an external dimension of migration policy. This relatively new field of EU external relations developed from internal policies within the realm of Home Affairs. Measures such as readmission agreements, extraterritorial border control and visa facilitation have been promoted in that context. The field is still sensitive from a sovereignty point of view but goes through continuous transformation and expansion. This study analyses the organisational dynamics in this field in connection to the role that constitutional principles play in shaping actors’ preferences and actions. The theoretical foundations of the study lie in organisations theory, specifically as developed by Swedish theorist Nils Brunsson.

The study analyses three organisations: 1) European Commission’s Directorate-General Home Affairs, 2) External Border Agency Frontex and 3) the European External Action Service. They constitute the most essential EU level organisations in the external dimension of migration policy. To understand how constitutional principles become relevant for those organisations, emphasis is given to the environments in which these organisations operate and their internal structures and cultures. Specifically, the ‘Rule of Law’ is taken to illustrate the way in which these organisations deal with constitutional principles.

However, this is all work in progress, so any input is welcome!    


Academic Activities


  • Presentation of paper on EU Home Affairs Agencies for the 'Migration and Citizenship Research Group' at the University of Edinburgh, March 2013
  • Presentation of paper 'The specific nature of EU Home Affairs Agencies: beyond accountability versus autonomy?' (co-presented with Joanna Parkin) at the UACES Annual Conference (Passau), September 2012 
  • Presentation of paper 'Constitutional principles and their role of legitimation in EU external relations - an organisations theory approach' at the ISA/BISA Conference (Edinburgh), June 2012
  • Presentation of paper 'EU Foreign, Security and Defence Policy: a Competence-Responsibility Gap?' at the Hebrew University (Jerusalem) Graduate Conference, December 2011
  • Presentation of paper 'Revolution and war at Europe's doorstep and the migratory consequences - implications for the external dimension of migration' at the Finnish Institute for International Affairs (Helsinki) seminar on 'The EU and its neighbours', September 2011
  • Presentation of paper 'Revolutions and their migrants: EU's solidarity and fundamental rights' at University of Surrey (Guildford) UACES conference on 'New frontiers in European Studies', June 2011. Click here for a UACES podcast interview with me on the subject.
  • Presentation of paper 'Policy Coherence in the EU System - concepts and legal rooting of an ambiguous term', with Simon Stross, at CEU Universidad San Pablo (Madrid) conference on 'EU as a global power', April 2011.
  • Presentation of paper 'Fundamental rights and the extraterritorialisation of EU border policy - a contradiction in terms?' at CEPS (Brussels) EU-Canada training school on 'The reframing of the EU external border - risk, ethnicity and nationality', February 2011 



  • L. den Hertog and S. Stroß, 'Coherence in EU External Relations: Concepts and Legal Rooting of an Ambiguous Term', European Foreign Affairs Review, Volume 18, Issue 3 (forthcoming).



  • Teaching and essay-writing supervision at the University of Cologne for a course on 'the EU as a global actor' together with EXACT Fellows Andreas Raspotnik and Peter Valant (November 2012 - February 2013).
  • Course organisation, teaching and essay-writing supervision at the University of Cologne for a course on 'EU external relations - with special focus on EU-Africa relations' together with EXACT Fellow James Nyomakwa-Obimpeh (April - July 2012).
  • Guest lecture at Széchenyi István University (Gÿor, Hungary) on 'the Rule of Law in the EU' in the course of prof. B. Horvathy (March 2012).
  • Guest lecture at ELTE University (Budapest) on 'EU Border Policy, Human Rights and Refugees in the Mediterranean Sea' in the Erasmus course of L. Balogh on 'Law and Ethnicity: From the Dilemma of Ethnic Identity-Formation to the Morphology of Minority Protection' (November 2011).
  • Two guest lectures at the Ethiopian Civil Service College (Addis Ababa) on 'Legal Philosophy' in the course of prof. Kundidzora on the same topic (October 2009).



  • Participation in 2-week EXACT Network Seminar on Academic Skills at the University of Cologne supervised by Prof. G. Edwards (University of Cambridge) and Dr. R. Kissack (Institut Barcelona d'Estudis Internacionals). Covered skills include: teaching, presenting, using theoretical and methodological approaches, publishing etc., September 2012
  • Participation in 1-week course 'Content Analysis' (lecturer: A. Bicquelet, London School of Economics) in the ECPR Summer School on Methods and Techniques at the University of Ljubljana, August 2012.
  • Participation in 2-week EXACT Network Seminar on Professional Skills at TEPSA (Brussels) supervised by Prof. H. Ojanen (University of Helsinki/Finnish Institute of International Affairs). Covered skills include: media training, public speaking, funding opportunities, project administration, management and coordination, interviewing and op-ed and policy brief writing, October 2011.
©  EXACT - Marie Curie ITN on EU External Action
Technische(r) Ansprechpartner(in):
Aline Bartenstein
Wulf Reiners
geändert: 21. May 2013
erstellt:  5. November 2010