Treaty of Amsterdam, which was signed in Amsterdam on 2 October 1997 and entered into force on 1 May 1999, and theTreaty of Nice, which was signed on 26 February 2001 and entered into force on 1 February 2003, amended both theTreaty establishing the European Community and theTreaty on European Union.
Leasaigh Conradh Amstardam a síníodh in Amstardam ar 2 Deireadh Fómhair 1997 agus a tháinig i bhfeidhm ar 1 Bealtaine 1999, agus Conradh Nice”, a síníodh ar 26 Feabhra 2001 agus a tháinig i bhfeidhm ar 1 Feabhra 2003, an Conradh ag bunú an Chomhphobail Eorpaigh agus an Conradh ar Aontas Eorpach araon.