In bright sunshine at the traditional heart of ancient democracy, the political leaders of 10 European states signed the treaty paving the way for their joining the European Union in May 2004, writes Mark Brennock, in Athens.
Some 14 years after the collapse of the Berlin Wall, seven former Soviet bloc states, a former Yugoslav republic and two Mediterranean island states marked the end of over a decade of negotiation and reform, expanding the EU to 25 members.
"Today is a historic day because we are overcoming the divisions of a continent that was once divided into two camps, east and west," declared Mr Costas Simitis, Prime Minister of Greece, which currently holds the rotating EU Presidency.
On a highly symbolic and emotional day for many of the new states, journalists and other media staff from the accession states applauded as they watched live television pictures in the giant press centre of their leaders signing the 5,000-page accession treaty.
Presuming the remaining ratification processes go smoothly, the 10 new states will finally join the Union on May 1st 2004 during Ireland's six-month Presidency of the EU. Hungary this week joined Slovenia and Malta in ratifying membership. Poland, the Czech Republic, Slovakia, Latvia, Lithuania, Estonia and Cyprus are expected to approve membership in referendums in the coming months.
The 10 new states will bring 75 million people into the EU - raising its population to 450 million. The newcomers' wealth ranges from barely 29 per cent of the EU average in Lithuania to 85 per cent in Cyprus.
The Taoiseach said at the ceremony that there was "no more fitting place to mark this important moment than Athens, in many respects the birthplace of European democracy, civilisation and culture". It would be Ireland's privilege, he noted, as holder of the EU Presidency in the first half of 2004, to welcome in the new states.
The ceremony took place between the shaded columns of the Attalos Stoa, a second-century BC covered market where, according to the Greek government, "the heart of the ancient Athenian democracy once beat".
Danish Prime Minister Mr Anders Fogh Rasmussen, whose government, as the EU president before Greece, did the hardest work in negotiating the enlargement deal, told the newcomers: "We welcome you to our family."