Mixed Arbitral Tribunals, 1919–1930:
An Experiment in the International Adjudication of Private Rights

29–30 April 2021

The creation of a system of Mixed Arbitral Tribunals (MATs) was a major contribution of the post-WWI peace treaties to the development of international adjudication. Numerically speaking, the 36 MATs were undoubtedly the busiest international courts of the interwar period. Taken together, they decided on more than 70,000 cases, mostly covering private rights. This caseload is even more impressive if one considers that their existence generally did not exceed 10 years, as most of the MATs were discontinued pursuant to the 1930 Young Plan. The MATs are similarly remarkable from a procedural point of view. First, their respective rules of procedure were so detailed that contemporaries described them as 'miniature civil procedure codes'. Second, in a departure from most other international courts and tribunals, they also allowed individuals whose rights were at stake to become involved in the proceedings before them. Although the MATs failed to produce a universally consistent body of case-law, their collection of published decisions was a major source for legal doctrine in the 1920s and 1930s and remains of interest for international lawyers today. The MATs themselves served as a source of inspiration for other international and supranational courts and tribunals, including the European Court of Justice. Their example might similarly inspire potential future negotiations over institutionalized investment tribunals.

And yet, like many other international 'experiments' of the interwar period, the MATs are often barely mentioned in post-WWII accounts of international law. Despite (or perhaps because of) the amount of cases they handled and the vastness of archival records they generated, they have not given rise to a single major monograph after 1945.

By organizing a conference specifically dedicated to the MATs and their impact on international adjudication of private rights, the Max Planck Planck Institute Luxembourg for Procedural Law would like to shed new light on this often overlooked chapter in the history of international law.

Thursday, 29 April 2021

14:00 Welcome coffee
14:30 Welcome Address: Prof. Hélène Ruiz Fabri & Dr Michel Erpelding (MPI Luxembourg)
14:45 Session 1: A New Form of International Adjudication: The MATs in Context
Introductory Speaker: Dr Jakob Zollmann (WBZ Berlin Social Science Center)
Dr José Gustavo Prieto Munoz (University of Turin)
Mexican Claims Commissions and Caudillos in the 20th Century: The Legitimacy for International Adjudication in Latin America
Mr Willem Theus (Catholic University of Leuven - KUL)
There and Back Again: From Consular Courts Through Mixed Arbitral Tribunals to International Commercial Courts
Dr Zülâl Muslu (MPI European Legal History)
'The Mixed Arbitral Tribunals and Turkey: Negotiating the International Identity of the Young Republic Under the Sèvres Syndrome'.
Chair: Dr Jakob Zollmann (WBZ Berlin Social Center)
16:15 Coffee break

16:45 Session 2: Identifying the Claimants: The MATs and the Nationality of Private Persons
Dr Jakob Zollmann (WBZ Berlin Social Science Center)
The Mixed Arbitral Tribunals and Citizenship. Histories of Nations, Autonomy and Anger, 1919 to 1930
Mr Momchil L. Milanov (University of Geneva)
Splitting the Atom of Nationality: The Mixed Arbitral Tribunal for Upper Silesia and the Emergence of Citizenship in International Law
Prof. Emanuel Castellarin (University of Strasbourg) *
The Mixed Arbitral Tribunals and the Nationality of Legal Persons
Chair: AG Maciej Szpunar (Court of Justice of the European Union) TBC
18:00 Reception

Friday, 30 April 2021

Morning session
09:00 Welcome coffee
09:30Session 3: Arbitrators as Peacemakers: The Case of Prof. Paul Moriaud (1865-1924)
Dr Pascal Plas (University of Limoges)
Paul Moriaud, la paix par l'arbitrage, L'homme, les réseaux, les idées (FR)
Prof. Jacques Péricard (University of Limoges)
Paul Moriaud et la mise en oeuvre des Tribunaux arbitraux mixtes (FR)
Dr Michel Erpelding (MPI Luxembourg)
Paul Moriaud, the German-Belgian MAT, and the Case of the Belgian Deportees
Chair:Prof. Emmanuel Decaux (OSCE Court of Conciliation and Arbitration)

11:15Coffee break
11:45Session 4: Arbitral Awards as Sources of International Law: Assessing the Impact of the MATs' Case-Law
Mr Guillaume Guez (University of Geneva; Sorbonne Law School)
The Contribution of the MATs to the Law of Treaties
Dr Mateusz Piatkowski (University of Lodz)
The MATs and the Law of Air Warfare: The Tragic Impact of the Awards in Coenca Brothers and Kiriadolou
Chair:Prof. Hélène Ruiz Fabri (MPI Luxembourg)
13:00Lunch break
Afternoon session
14:00Session 5: The MATs and the Protection of Private Property: From the Interwar Period to Present-Day Debates on Investor-State Arbitration
Dr Marilena Papadaki (University of Athens)
The Romanian-Hungarian MAT: Protection of Enemy Private Property, Questions of Jurisdiction, and the Council of the League of Nations 
Prof. Maja Stanivukovic & Dr Sanja Djajic (University of Novi Sad)
Something Old, Something New: The 1930 Reform of the Trianon MATs and the Contemporary Discussion of the Appeal Mechanism in Investment Arbitration
Dr Jarrod Hepburn (University of Melbourne)
Investment Treaty Arbitration and the Nascent Legacy of the MATs
Chair:Porf. Hans Van Houtte (Catholic University of Leuven (KUL) / Iran-United States Claims Tribunal)
15:45Concluding Remarks: Prof. Burkhard Hess (MPI Luxembourg)
* The outline sent by this author will be presented by the organisers.
If you are interested in participating in this event, please send an email to events@mpi.lu.
Participation is free of charge.

Transnational Dispute Management (TDM, ISSN 1875-4120) is a comprehensive and innovative information service on the management of international disputes, with a focus on the rapidly evolving area of investment arbitration, but also in other significant areas of international investment (such as oil, gas, energy, infrastructure, mining, utilities etc).
It deals both with formal adjudicatory procedures (mainly investment and commercial arbitration), but also mediation/ADR methods, negotiation and managerial ways to manage transnational disputes efficiently. See www.transnational-dispute-management.com for more information. You can apply for a free OGEMID trial membership and students can sign up for Young-OGEMID (which is free).

Max Planck Institute Luxembourg
Conference room, 4th floor
4, rue Alphonse Weicker
L-2721 Luxembourg