HISTORY OF THE
EUROPEAN UNION 
Chronologies
A Yearly Chronology of the European Union.
Treaties and law of the European Union.
Historical Archives
EURHISTAR - Database of the Historical Archives of the European Communities managed by the European University Institute in Florence.
Collections
A site dedicated to the History of European Integration provided by the University of Leiden.
EuroDocs: Primary Historical Documents from Western Europe - This link connects you to Western European (mainly primary) historical documents that are transcribed, reproduced in facsimile or translated.
The Avalon Project at the Yale Law School contains documents relevant to the field of Law, History, Economics, Politics, Diplomacy and Government.