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13:00in productionCh. 1 · Six signatures on Capitoline Hill/ 13:00 · ceiling 15 min
20th century · Economy & trade

Treaty of Rome

1957

Six countries signed a customs-union treaty on a hill in Rome in 1957 without political union in mind, and the institutions it created still ended up absorbed into a political union anyway, decades later.

Signed on 25 March 1957 on Capitoline Hill in Rome and effective from 1 January 1958, the Treaty of Rome established the European Economic Community among Belgium, France, Italy, Luxembourg, the Netherlands and West Germany, alongside a companion treaty founding the European Atomic Energy Community. Built on the 1955 Spaak Report and negotiations at Val Duchesse, it created a customs union intended to foster economic integration, and its institutions were later merged with those of the earlier Coal and Steel Community before evolving, through the Maastricht and Lisbon treaties, into the European Union.

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Chapters & takeaways6
  1. 0:08
    Six signatures on Capitoline Hill

    Belgium, France, Italy, Luxembourg, the Netherlands and West Germany signed the treaty on 25 March 1957, and it took effect on the first day of 1958.

  2. 2:10
    A well-preserved treaty text, a thinner record of the room

    The treaty's provisions are documented in full, but the specific negotiating exchanges among the six founding governments are recorded only sparsely in comparison.

  3. 4:20
    A defence union's failure led to an economic one

    Jean Monnet turned to economic integration only after the French parliament rejected a proposed European Defence Community, redirecting momentum toward a customs union instead.

  4. 6:30
    What is actually settled about the treaty's founding, and what is not

    The names of the negotiators most closely involved in the Val Duchesse talks are less firmly established in the record than the treaty's final, agreed text.

  5. 8:40
    From a customs union to a political union

    The 1967 Merger Treaty, the 1993 Maastricht Treaty and the 2009 Treaty of Lisbon successively expanded the Community's institutions into the European Union.

  6. 10:50
    Worth reading for how modest its original ambitions were

    The treaty rewards attention because it was written to build a customs union, not the political union its institutions eventually became part of.

Worth your time?

Selectively. Start with the brief, then study the parts we point at.

3/ 5
What works
  • the sequence from the Messina Conference through the Spaak Report to the signed treaty is presented clearly
  • the six founding member states and the treaty's effective date are stated without ambiguity
  • the later institutional path, through the Merger Treaty, Maastricht and Lisbon, is traced in a way that shows continuous development rather than a single fixed moment
What does not
  • the individual negotiators present at Val Duchesse beyond Paul-Henri Spaak's preparatory report are not clearly identified in the source material
  • the treaty's own provisions are described only in general terms rather than through specific articles
Study it if
  • readers interested in how narrow economic agreements can grow into much larger political structures
  • readers who want the sequence from Coal and Steel Community to Common Market to European Union laid out plainly
  • anyone curious about the six founding states before later waves of enlargement
Skip it if
  • readers wanting a detailed account of the actual negotiating sessions among the six governments
  • readers looking for the treaty's individual articles explained clause by clause
The written brief3 min read

Six signatures on Capitoline Hill

The Treaty of Rome was signed on 25 March 1957 at the Palazzo dei Conservatori on Capitoline Hill, with the government of Italy serving as depositary, and it entered into force on 1 January 1958. It established the European Economic Community among six founding states, Belgium, France, Italy, Luxembourg, the Netherlands and West Germany, and a companion agreement signed the same day founded the European Atomic Energy Community, known as Euratom, to govern civilian nuclear cooperation among the same six countries. The two treaties together gave the new Community its founding legal basis, separate from the earlier European Coal and Steel Community that had linked the same states since the start of the decade.

A well-preserved treaty text, a thinner record of the room

The treaty’s agreed text is preserved and its basic facts, the date, the location, the six signatory states, are not disputed. Less fully documented in accessible sources is the detailed record of the negotiating sessions themselves, held at the Val Duchesse chateau near Brussels in 1956. The 1955 Spaak Report, prepared by Belgian foreign minister Paul-Henri Spaak following the Messina Conference, is well established as the foundational document guiding those talks, alongside a companion study known as the Ohlin Report, but the individual contributions of other national negotiators during the Val Duchesse sessions receive comparatively thin coverage next to the treaty’s own finished language.

A defence union’s failure led to an economic one

The path to Rome ran through an earlier failure. Jean Monnet, president of the Coal and Steel Community’s High Authority, had backed a proposed European Defence Community aimed at political and military integration, but the French parliament rejected it. Monnet resigned from the High Authority in protest and turned instead to pursuing integration through economic rather than political means, work that fed into the Messina Conference of 1955 and the subsequent Spaak Report. That shift in strategy, from a defence union that had failed to a customs union that succeeded, shaped the more limited, trade-focused character of the treaty eventually signed in Rome two years later.

What is actually settled about the treaty’s founding, and what is not

What is firmly established is the treaty’s basic structure and founding membership; what is less clear from the available record is exactly how negotiations unfolded session by session at Val Duchesse, and which national representatives shaped specific compromises beyond Spaak’s own preparatory report. The source material itself notes gaps in citation regarding the treaty’s negotiation and reception, meaning that while the final agreed document is not in question, the finer texture of how six governments arrived at that text, and how contested particular provisions were before signature, remains less thoroughly documented than the treaty’s eventual content and consequences.

From a customs union to a political union

The Community’s institutions did not remain static. The 1967 Merger Treaty combined the governing bodies of the Coal and Steel Community, the Economic Community and Euratom into a single institutional structure. Membership expanded in 1973 with Denmark, Ireland and the United Kingdom, and again in the 1980s with Greece, Spain and Portugal. The 1993 Maastricht Treaty transformed the Economic Community into the European Community and established the broader European Union with its three-pillar structure, and the 2009 Treaty of Lisbon dissolved that pillar system, folding the Community fully into the Union, more than half a century after six states had signed a much narrower customs-union agreement in Rome.

Worth reading for how modest its original ambitions were

The treaty is worth reading with an eye to how limited its original scope actually was: an agreement among six states to build a customs union and cooperate on nuclear energy, not a blueprint for the political and monetary union its institutions eventually grew into. Readers who know the European Union mainly through its later, larger form gain the most from seeing how far the 1957 starting point sits from that outcome, and how many separate treaties, Merger, Maastricht, Lisbon, were needed to carry the six founders’ modest customs arrangement toward something closer to political integration.

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