Eurostat provides high-quality statistics and data on Europe dating back to the 1950s.
The coverage of some topics started later, in parallel with EU policy developments. A summary of the main steps is available on
Eurostat webpage History .

For questions on European statistics, Eurostat offers a multilingual user support service .

IATE (Interactive Terminology for Europe) is the EU's terminology management system. IATE covers also historical terminology.

EUR-Lex is your online gateway to EU law. It provides the official and most comprehensive access to EU legal documents dating back to the beginning of the European Union.

See for example

Official Journal (from the first edition in 1952 until today)

Chronological overview of the Treaties

The Court of Justice of the EU's InfoCuria database contains all the publicly available information concerning the cases brought before the Court of Justice, the General Court and the Civil Service Tribunal.

DORIE (which stands for DOcumentation et Recherche sur les questions Institutionnelles Européennes) is a database providing access to the collection of documents put together over the years by the unit in the Secretariat-General responsible for institutional issues. The time period covered in DORIE goes from 1946 (oldest document available in the application) until nowadays.

European University Institute, EUI research repository (accessed 3 June 2025)

Cadmus is the EUI Research Repository, collecting, preserving & providing access to the EUI research outputs according to the EUI Open Access policy. Cadmus collects and provides access to both scholarly publications and research data.

A collection of research guides has been elaborated to provide a general overview of the archival material available at the HAEU to conduct research on specific topics pertaining to European integration and policies developed at the European level.