1969 1st December
Hague Summit Relaunch
Pompidou backed completion, deepening and enlargement of the Communities at the Hague summit.
European integration · permanent subject timeline
First EEC Enlargement, 1973
Denmark, Ireland and the United Kingdom join the European Communities. This page combines historical context with 15 matching records drawn directly from the World History Database EEC archive.
Historical context
First EEC Enlargement, 1973: overview and significance
What happened?
After years of applications, negotiations and political disputes, Denmark, Ireland and the United Kingdom joined the European Communities on 1 January 1973.
Why was it important?
The first enlargement changed the Community from six members to nine and demonstrated that the integration project could expand beyond its original continental core.
World History Database records
First EEC Enlargement, 1973 timeline
The records below are selected from the 936-record EEC and European integration archive and rendered as static HTML in chronological order.
1969
1969 1st December
Hague European Summit
Represents Germany as leaders open the Hague summit on completion, deepening and enlargement of the European Communities.
1969 1st December
Hague European Summit
Represents Italy as Community leaders open the Hague summit on completion, deepening and enlargement.
1969 2nd December
Hague Enlargement Decision
Supports the Hague agreement to open enlargement negotiations with applicant countries including Britain, Denmark and Ireland.
1969 2nd December
Hague Enlargement Decision
Supports the Hague agreement to begin enlargement negotiations and strengthen European cooperation.
1971
1971
Enlargement Negotiations
Pompidou supported completion of negotiations for Britain, Ireland, Denmark and Norway to join the Communities.
1972
1972 22nd January
Accession Treaty Support
Pompidou supported the treaties enabling Britain, Ireland, Denmark and Norway to seek membership of the European Communities.
1972 22nd January
First Enlargement Treaty
Heads the German government when accession treaties are signed with Britain, Denmark, Ireland and Norway.
1972 22nd January
First Enlargement Treaty
Heads the Italian government when accession treaties are signed with Britain, Denmark, Ireland and Norway.
1972 23rd April
French Enlargement Referendum
French voters approved enlargement of the European Communities in a referendum called by Pompidou.
1973
1973 1st January
First Community Enlargement
France welcomed Denmark, Ireland and the United Kingdom into the European Communities, increasing membership from six to nine.
1973 1st January
First EEC Enlargement
Heads the German government as Denmark, Ireland and the United Kingdom join the European Communities.
1973 1st January
Britain Joins European Communities
Britain officially becomes a member of the EU
1973 1st January
Ireland Joins European Communities
Heads the government when Ireland becomes a member of the European Communities.
1973 1st January
First EEC Enlargement
Heads the Italian government as Denmark, Ireland and the United Kingdom join the European Communities.
Editorial provenance
Sources and editorial review
Compiled and edited by World History Database.
Historical context is editorial material; the chronology is generated from World History Database EEC records.
Last reviewed: September 2026.
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