“The European Union (EU) is a unique economic and political union between 27 European countries.” https://op.europa.eu/webpub/com/eu-what-it-is/en/
This guide lists useful resources and databases to get you started with EU legal research.
Westlaw EU materials include cases, legislation, treaties, preparatory acts, information/notices, selected treatises and journals.
Westlaw UK Includes cases, legislation, information/notices, preparatory acts, and treatises. On the Welcome page, select EU from the tabs at the top of the Welcome Page.