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European Union Documents: Treaties

Treaty Sources

Europa / EurLex
Contains copies of the EU treaties at the following link :

Nexis Uni
Database Name: EU Law (Celex); EU Treaties
Contains founding treaties since 1951 ; derived from the CELEX database

The official legal database of the EU is available by subscription only. EurLex (discussed above) provides access to a portion of the content available on CELEX. CELEX provides content prior to 1998 and allows for advanced searching capabilities. Princeton University does not subscribe to this fee database published by the European Union Office of Publications because much of the content is available through other databases, such as LexisNexis, or in the print or microforms collection.

Copies of the treaties are available in the following treaty series or serials:


United Nations Treaty Series
Holdings: 1946-47 - present


European Yearbook
JN3 .A5 
Firestone Library (F)  Vol. 1 (1955) -
Trustee's Reading Room, Firestone Library  (current volume)

International Legal Materials
Holdings: Vol. 1 (1962) -

Founding Treaties

Founding Treaties
EUR-LEX contains copies of the constitutive treaties.
The text of the treaties are usually published in the Official Journal of the European Communities, the principal legal publication of the EU. Other treaty series and commercial publications are also sources for the text of treaties. For U.S. attorneys, the O.J. is roughly equivalent to a combination of the Federal Register, the Statutes at Large and the United State Treaty Series.

The founding treaties are frequently referred to as "primary legislation." In contrast, "secondary legislation" refers to directives, regulations and other forms of law described in the LEGISLATION section below.

For a list of the founding treaties, see Research Guide: European Union Law Materials (Columbia University Law School).

Accession Treaties

Accession Treaties

The EU has grown since its founding by admitting additional nations. New members of the EU must sign and ratify an accession treaty in order to join the EU.   For a list of the accession treaties, see Research Guide: European Union Law Materials (Columbia University Law School).