As the clock struck midnight and Saturday 1 May arrived, a variety of celebrations, orthodox and unorthodox, were launched in the accession countries across central Europe.

The historic expansion was hailed as a pinnacle of the efforts to build lasting peace on the continent after centuries of war. Nevertheless it was accompanied by widespread anxiety about the economic impact, particularly for citizens of the current 15 members. Reflecting that concern, celebrations in most west European capitals were low-key. The exception was Dublin, not only the furthest west but as current holder of the EU Presidency the host for the first summit of the enlarged European Union of 25 members.

But in central and Baltic Europe, the move from their long legacy of Iron Curtain isolation has been celebrated in a number of original ways.

In Estonia, some 20,000 people will plant a million trees. In neighbouring Lithuania, citizens will switch on lights at their homes at the stroke of midnight to make the country glow on the satellite image of Europe.

In Hungary the mayor of Budapest Gábor Demszky has called on his citizens to enter the EU without the baggage of the past. He asked them symbolically to dump their unwanted belongings at the city's central square Deák tér.

In the Czech Republic, mist from water cannons and floodlights created at several places on its national borders a rainbow linking "old" and "new" Europe, symbolising the end of the continent's division after World War Two.

Poland is the largest new member with nearly 40 million people - there, scouts in the central city of Lodz were busy sewing what they called the world's largest map of Europe, which will cover the whole of the city's main square. Many of the citizens of Warsaw left for their summer cottages - schools and government offices in central Warsaw had been shut down, making enlargement one of the longest holiday weekends in years.  There were also official state-sponsored celebrations and private parties in Warsaw. In contrast the Catholic Church, which only recently converted from earlier euro-scepticism into euro-enthusiasm, called on the faithful to fast on May Day to show solidarity with the poor.

Slovakia joins EUrope

Slovakia joined the European Union on 1 May, along with nine other countries of central and eastern Europe. It is widely seen as the most important event in the country's modern history. "We have been enriched by a new, European identity," said Prime Minister Mikuláš Dzurinda in a public address on 1 May. "Slovakia's entry into the EU is perhaps the greatest challenge we will go through in our lives," said Speaker of Parliament Pavol Hrušovský at a ceremonial session of the legislature on 30 April. "It is certainly among the four key events of our most recent history, along with [the fall of the communist regime in] November 1989, the creation of an independent Slovakia [in 1993], and NATO entry." One MP who did not attend the session was Vladimír Mečiar, former PM and head of the opposition party Movement for a Democratic Slovakia (HZDS). In the years 1994 to 1998 his government had been the main obstacle to Slovakia's hopes of participation in this round of enlargement. Meciar was thought not yet to have recovered from the defeat he suffered in the second round of presidential elections held on 17 April. "For the first time in history, Slovakia can decide not only about its own future, but take part in deciding the future of Europe. It will be up to us to decide how to seize this opportunity," said Foreign Minister Eduard Kukan as the EU flag was raised in front of his office.

Ethnic Russians protest while EU entry celebrated

Celebrations in Latvia to mark entry into the European Union were marred by protests on 1 May as thousands of ethnic Russians rallied to call for better protection of their rights.

Almost a third of the 2.3 million people in Latvia are descendants of ethnic Russians who came to live in Latvia during the Soviet era. Many of them are sceptical of the EU. A crowd of around 20,000 protesters gathered at the Victory Monument, which marks the Soviet army's defeat of Nazi Germany during World War 2.

Protesters of all ages had earlier marched through Riga wearing signs saying "Alien" in reference to their non-citizen status. They will need visas to work and travel in the EU. "Stop apartheid in Latvia!" read one banner. The rally was also linked to an education reform that restricts the use of Russian language in schools.

As thousands thronged into a square in Riga's historic Old Town to hear President Vaira Vike-Freiberga address the nation, protesters at the Victory Monument waved crossed-out EU-flags and sang Pink Floyd's "Another Brick in the Wall" in Russian.