Dr Sotirios Ioannis Lekkas (he/him)

School of Law

Lecturer in International Law

Deputy Director of 91探花 Centre for International and European Law (SCIEL)

Staff photo of Sotirios I Lekkas
Profile picture of Staff photo of Sotirios I Lekkas
s.i.lekkas@sheffield.ac.uk
+44 114 222 6765

Full contact details

Dr Sotirios Ioannis Lekkas
School of Law
EF15b
Bartolome虂 House
Winter Street
91探花
S3 7ND
Profile

I joined the University of 91探花 in September 2023. My expertise lies in the field of general international law and, specifically, the law of international responsibility and interpretation. I have also conducted research in various specialised fields of international law including the law of the sea, international criminal law, and international investment law. My current project studies the content and evolution of international rules of interpretation across different sources and different subject matters.

Prior to joining 91探花, I was lecturer in Public International Law at the University of Groningen, the Netherlands and postdoctoral researcher for the ERC-funded project 鈥楾he Rules of Interpretation of Customary International Law鈥 (TRICI-Law). I have also worked as a judicial fellow at the International Court of Justice and taught public international law for the Faculty of Law of the University of Oxford. Other prior engagements include research positions at the British Institute of International and Comparative Law and the University of Athens.  

I completed my doctoral dissertation on the intersections between the law of state responsibility and international criminal law at the Faculty of Law of the University of Oxford. I have studied law at the University of Athens (LLB; LLM) and University College London (LLM), where I was awarded the Schwarzenberger Prize in International Law by the Institute of Advanced Legal Studies, University of London. I am also a member of the Bar in Athens, Greece.
 

Qualifications
  • DPhil, University of Oxford
  • LLM (Dist), University College London 
  • LLM (Dist), University of Athens
  • LLB, University of Athens
Research interests
  • Law of International Responsibility
  • Sources of International Law
  • International Criminal Law
  • International Law of the Sea
  • International Law of Armed Conflict
  • International Investment Law
  • International Legal History and Theory
Publications

Journal articles

  • Lekkas SI, Merkouris P & Peat D (2023) . Max Planck Yearbook of United Nations Law, 26(1), 316-357. RIS download Bibtex download
  • Lekkas S-I (2022) . Proceedings of the ASIL Annual Meeting, 116, 217-220. RIS download Bibtex download
  • Lekkas S-I & Merkouris P (2022) . Netherlands International Law Review, 69(2), 183-189. RIS download Bibtex download
  • Lekkas S-I (2022) . Netherlands International Law Review, 69(2), 327-359. RIS download Bibtex download
  • Lekkas S-I (2021) . European Journal of International Law, 32(4), 1353-1359. RIS download Bibtex download
  • Lekkas S-I & Papastavridis E (2016) . Yearbook of International Environmental Law, 27, 561-564. RIS download Bibtex download
  • Lekkas S-I () . Global Intellectual History, 1-9. RIS download Bibtex download

Chapters

  • Lekkas S-I (2024) In Merkouris P, Kulick A, 脕lvarez-Zarate J-M & 呕enkiewicz M (Ed.), Custom and its Interpretation in International Investment Law (pp. 93-122). Cambridge University Press RIS download Bibtex download
  • Lekkas S & Staker C (2017) In Proelss A (Ed.), United Nations Convention on the Law of the Sea : A Commentary Nomos Verlagsgesellschaft RIS download Bibtex download
  • Lekkas S-I & Tzanakopoulos A (2014) , Research Handbook on the Law of Treaties Edward Elgar Publishing RIS download Bibtex download
Research group
  • Law of International Responsibility
  • Sources of International Law
  • International Criminal Law
  • International Law of the Sea
  • International Law of Armed Conflict
Teaching interests
  • Public International Law
  • International Law of the Sea
  • International Criminal Law
  • International Law and Armed Conflict
  • International Investment Law
  • International Dispute Settlement
Teaching activities

Undergraduate 

  • Foundations of International Law
  • Advanced International Law

Postgraduate

  • International Law of the Sea
Professional activities and memberships

Deputy Director of the 91探花 Centre for International and European Law