Starting with 1st of July 2013 Croatia has become the 28th member of the European Union, with crowds joining celebrations in the capital Zagreb.
Fireworks lit the sky as membership became effective at midnight on Sunday, with President Ivo Josipovic describing the event as historic.
It comes almost two decades after Croatia’s brutal war of independence.
But correspondents say enthusiasm for the EU in the country has been dampened by the eurozone crisis, and Croatia’s own economic problems.
Celebrations took place in the central square of Zagreb, with fireworks and music including Beethoven’s Ode to Joy, the European anthem.
“Welcome to the European Union!” European Commission President Jose Manuel Barroso said in Croatian to the cheering crowd.
President Ivo Josipovic said it was “a great and joyful day for our homeland”.
“This the day when we open a new chapter in the thick book of our history,” he added.
Starting with 1st of July 2013 Croatia has become the 28th member of the European Union
Earlier he told a meeting of EU and regional leaders: “The accession of Croatia to the European Union is confirmation that each one of us belongs to the European democratic and cultural set of values.”
Croatian officials then unveiled EU signs and removed customs posts at the borders with Slovenia, the first former Yugoslav republic to have joined the bloc, and with Hungary.
Croatia is the first new EU member since Romania and Bulgaria joined in 2007. It is 10 years since it applied.
Croatia’s split from Yugoslavia triggered a 1991-1995 war to secure its independence.
But with one in five unemployed and Croatia’s national debt officially classed as junk, some Croatians feel joining an economic bloc with its own serious troubles will do little to improve their prospects.
“Just look what’s happening in Greece and Spain! Is this where we’re headed?” asked pensioner Pavao Brkanovic in a market in the capital.
“You need illusions to be joyful, but the illusions have long gone,” he told Reuters news agency.
Concerns about Croatian corruption and organized crime remain among some EU leaders, and Croatia will not yet join the single currency nor the visa-free Schengen zone.
But advocates of EU membership say despite this, their case remains a persuasive one.
Two-thirds of Croatians voted in favor of accession last year.
“It’s important for us primarily for the long term guarantees of political stability and then everything else – the single market too,” said Croatia’s First Deputy Prime Minister, Vesna Pusic.
The EU itself has given Croatia a clean bill of health – and praised reforms which improve the rule of law and tackle corruption.
It hopes the other countries of the former Yugoslavia will be encouraged to join – and secure long-term peace for an historically turbulent region.
The presidents of the EU’s three main institutions have collected the Nobel Peace Prize in Oslo, Norway.
The EU was awarded the prize for its role in uniting the continent after two world wars.
At the ceremony there was applause when the leaders of France and Germany stood up, holding hands.
Critics say the award is inappropriate. They point out that the eurozone crisis has exposed deep divisions in the 27-nation bloc.
Most of Europe’s national leaders were at the event, but not the UK’s David Cameron.
The British prime minister’s deputy, Nick Clegg – a longstanding advocate of the European project – represented the UK at the ceremony.
Nobel committee chairman Thorbjoern Jagland told the audience that in the current economic crisis “the political framework in which the union is rooted is more important than ever”.
“We must stand together, we have collective responsibility,” he said, warning of a risk of new nationalism in Europe.
The prize was received jointly by European Council President Herman Van Rompuy, European Commission President Jose Manuel Barroso and European Parliament President Martin Schulz. Herman Van Rompuy and Jose Manuel Barroso then gave a joint acceptance speech, in two parts.
The presidents of the EU’s three main institutions have collected the Nobel Peace Prize in Oslo
Herman Van Rompuy paid tribute to the post-war leaders of France and Germany who had forged the EU by uniting their economic interests.
He praised “the EU’s secret weapon – an unrivalled way of binding our interests so tightly that war becomes impossible”.
“It is better to fight around the table than on a battlefield,” he said, quoting Jean Monnet, one of the EU’s founders.
German Chancellor Angela Merkel sat next to French President Francois Hollande at the ceremony in Oslo City Hall.
Herman Van Rompuy said the economic crisis was fuelling “the return of long-forgotten faultlines and stereotypes”, but added: “Even such tensions don’t take us back to the darkness of the past.”
He ended by adapting the famous “Ich bin ein Berliner” quote from the late President John F. Kennedy during the Cold War.
He said he hoped future generations would “say with pride <<Ich bin ein Europaer>>, <<Je suis fier d’etre Europeen>>, <<I’m proud to be European>>.”
Four young Europeans, selected through an open EU competition, were in the delegation with equal status alongside the politicians.
The European Commission, which drafts EU laws, says the Nobel Prize money – about 930,000 euros ($1.2 million) – “will be allocated to children that are most in need”.
There has been a barrage of criticism – from Euroskeptics, peace activists and former winners of the prize.
Many of them question whether the EU should be given such an honor at a time when record unemployment and tough austerity policies, supported by European institutions, are causing serious social tensions in several member states.
European Commission President Jose Manuel Barroso is heading to Athens for talks on Thursday amid concern over whether Greece has done enough to get its next tranche of bailout loans.
It is his first visit for three years and he is expected to say the EU wants Greece to stay in the eurozone.
But there will be tough talking behind the scenes, analysts say.
Greece’s international lenders are also in Athens in an attempt to get deficit cutting measures “back on track”.
After months of political deadlock and two general elections earlier this year, Greece is struggling to meet the economic targets it has accepted as a condition of its bailouts.
Jose Manuel Barroso is heading to Athens for talks on Thursday amid concern over whether Greece has done enough to get its next tranche of bailout loans
Inspectors from the EU and the IMF are trying to work out whether or not Greece has done enough to receive its next tranche of loan money.
The European Commission says the country’s financing needs will be met in August, but a decision on further payments will have to be made in early September.
Without sufficient progress, it may not receive the final part of its bailout worth 31.5 billion Euros ($38 billion).
Earlier in the week, Prime Minister Antonis Samaras said Greece would suffer a much deeper recession than thought this year.
He expects the economy to shrink by 7%, greater than the 5% forecast by the crisis-hit country’s central bank.
Antonis Samaras said Greece would not return to growth until 2014.
He is expected to ask for more time to repay its loans.
Jose Manuel Barroso’s visit is overdue as Greeks often complain about European political leaders who spend plenty of time talking about them, and not much talking to them.
The Commission president is unlikely to be out and about shaking hands, but at least he will be in Athens to speak directly to the Greek people.
Jose Manuel Barroso’s spokesman said the purpose of his visit was “to meet Antonis Samaras and discuss the overall economic situation in Europe and in particular in Greece”.
He said it was “a regular meeting” and that the preparation for the talks had been “under discussion for some time”.