The article revisits the Barcelona Traction judgment of the International Court of Justice, rendered forty years ago. It evaluates the lasting influence of the Court's pronouncements on the nationality of corporations and on obligations erga omnes, and uses the case to illustrate the Court's role as an influential agent of legal development. In this respect, it identifies a number of factors that can help to explain under which circumstances judicial pronouncements are likely to shape the law.

Nationality of Corporations — Fictitious siège social — Test of Control.

Nationality of Corporations — Siège social — Theory of Control — Article 246 of Treaty of Trianon.

Treaties — Interpretation of — Construction of Identically Worded Provisions Contained in Different Treaties — Construction of Disputed Clauses by Reference to Other Treaties — Conflict between Provisions of Different Treaties — Interpretation of the Treaty of Trianon by Reference to Provisions of the Treaty of Versailles — Articles 297 and 250 of the Treaties of Versailles and Trianon Respectively — Nationality of Corporations — Theory of Control — Recourse to Preparatory Work.

Treaties — Interpretation of — International Conventions Concerning Jurisdiction of International Tribunals — Presumption against Inclusion of Nationals of Third States.

Arbitration — Jurisdiction of International Tribunals — Presumption against Inclusion of Nationals of Third States.

Nationality of Corporations — Siège social — Traditional Doctrine — Theory of Control — Theory Adopted by the Treaty of Versailles.

Jurisdiction — Exemptions from — Foreign Governments — Whether a Party is a Government or a Separate Entity — Status of Russian Volunteer Fleet.

Nationality of Corporations — Status of Russian Volunteer Fleet 1918–1922.

Jurisdiction — Exemptions from — Foreign Government — Conclusiveness of Claim to Property Made before English Court — Waiver of Claim to Property by Foreign Government.

Nationality of Corporations — Enemy or Neutral Character of a Corporation — Brazilian Company Founded and Conducted by Germans — Shipment from Brazil to Sweden, with Ultimate Destination to Germany — Insurance of Cargo against Molestation — Formal Criterion of Place of Registered Office, or Substantial Criterion of Nationality of Founders and Managers.

Nationality of Corporations — Change of Sovereignty — Provisions of Treaty of Peace between Allied and Associated Powers and Austria — Inclusion within the Term “Nationals of “former Austrian Empire.”

Nationality of Corporations — Theory of Control — Nationality of the Ottoman Bank.

Nationality of Corporations — Siège Social — Nationality of Members Decisive.

Nationality of Corporations — Siége Social — Spanish Subjects as Members of a Partnership Registered in France.

Nationality of Corporations — Theory of Control — Siège Social — Article 72 of the Treaty of Versailles.