Merger Treaty — treaty merging the institutions of the ECSC, EEC, and Euratom into the European Communities
The Merger Treaty unified the executive institutions of the ECSC, EEC, and Euratom under single shared bodies, forming the European Communities.
Key Facts
- Date signed
- 8 April 1965
- Entered into force
- 1 July 1967
- Communities merged
- ECSC, EEC, and Euratom
- Also known as
- Treaty of Brussels
- Abrogated by
- Amsterdam Treaty, signed 1997
By the Numbers
Location
Cause → Event → Consequence
By the mid-1960s, three separate European communities — the ECSC, EEC, and Euratom — each maintained their own executive bodies. This duplication of institutions created administrative inefficiency and complexity, prompting member states to seek a consolidation of governance structures while preserving the legal distinctness of each community.
On 8 April 1965, the Merger Treaty was signed in Brussels, replacing the separate High Authority and two Commissions with a single Commission of the European Communities, and consolidating the three separate Councils into one Council of the European Communities. The treaty took effect on 1 July 1967.
Although each community remained legally independent, they now shared a unified Commission and Council alongside the already-shared Parliamentary Assembly and Court of Justice. The resulting European Communities structure is regarded by some as the effective foundation of the modern European Union. The treaty was later repealed by the Amsterdam Treaty of 1997.
Political Outcome
A single Commission and a single Council were established to govern the ECSC, EEC, and Euratom collectively as the European Communities.
Three separate executive bodies: the ECSC High Authority, the EEC Commission, and the Euratom Commission, plus three separate Councils
One unified Commission of the European Communities and one Council of the European Communities