Fittingly for an institution with no single leader, the EU sent three of its presidents to the Oslo ceremony for the 2012 prize, which critics including former Nobel laureate Desmond Tutu say is undeserved.
"Sixty years of peace. It's the first time that this has happened in the long history of Europe," Herman Van Rompuy, the president of the European Council, told Reuters before the ceremony.
"The facts prove that the European Union is a peacekeeping instrument of the first order," said Van Rompuy, who will collect the prize along with European Commission President Jose Manuel Barroso and Ma r tin Schulz, the president of the European Parliament.
Europe is suffering feeble economic growth or outright recession, soaring unemployment and a number of its member states are unable to pay their debts. It has been called the worst economic crisis since World War Two.
The economic pain has provoked social unrest in a number of member states, notably near-bankrupt Greece. However, the Nobel committee focused on the EU's role in reconciling the disparate, warring corners of the "old continent" - the overarching success being to turn Germany and France from enemies into allies.
German Chancellor Angela Merkel and French President Francois Hollande sat next to each during the ceremony, smiling and talking quietly to each other on several occasions.
From just six countries which agreed to pool their coal and steel production in the 1950s to 27 member states today - and 28 once Croatia joins next year - the EU now stretches from Portugal to Romania, Finland to Malta and sets rules and regulations that have a bearing on more than 500 million people.
"The stabilizing part played by the EU has helped to transform most of Europe from a continent of war to a continent of peace," the Nobel committee said on October 12 when it announced the EU had won, an unexpected decision.
"The division between East and West has to a large extent been brought to an end; democracy has been strengthened; many ethnically based national conflicts have been settled."
Van Rompuy said the prize was due recognition of what earlier generations had achieved in forging peace. "I was born after the war, I was the first generation in Europe that could make his life without war," Van Rompuy, 65, said in an interview.
Commission President Barroso, a former prime minister of Portugal who was part of the struggle to turn his country into a democracy in 1974, echoed those sentiments.
"It's a recognition of what has been achieved over the 60 years and at the same time, it's also an encouragement for the future," he told Reuters. "I think the message they give to us is that what you have built is something very precious, something that we should treasure, that we should keep."
Despite the warm words of unity and sense of common purpose, the EU and its major institutions were at odds after the announcement was made because they couldn't decide who should accept the award or who specifically was to be honoured.
In the end it was decided that the prize was for all Europeans, to be picked up by the heads of the three main EU institutions. Twenty EU leaders also chose to attend the ceremony, but British Prime Minister David Cameron, whose relationship with Brussels is tense, stayed away.
0.2 EURO CENTS EACH
Four young Europeans, including a 12-year-old Spanish girl and a 21-year-old woman from Poland, also attended the ceremony after winning competitions, and 20 EU heads of state and government flew in for the high-profile occasion.
The prize money of 930,000 euros will be given to projects that help children struggling in war zones, with the recipients to be announced next week. The EU has said it will match the prize money, so that a total of 2 million euros will be given to the selected aid projects.
That decision went some way to silence critics on Twitter and other social media sites who initially joked that if the award was for all Europeans then they should all share the prize money - which would equal about 0.2 euro cents each.
Commentators on social media haven't been the only critics of the award going to the EU, which for the past three years has been a virtual byword for disorder and indecision because of its failure to get on top of a sovereign debt crisis.
Tutu, a churchman who fought the apartheid system in his native South Africa, said last week that the EU did not deserve the award. On Sunday around 1,000 members of left-wing and human-rights groups marched through the streets of Oslo in protest, saying the EU was not a rightful beneficiary under the terms Alfred Nobel laid down in his will in 1895.
"Alfred Nobel said that the prize should be given to those who worked for disarmament," said Elsa-Britt Enger, 70, a representative of Grandmothers for Peace. "The EU doesn't do that. It is one of the biggest weapons producers in the world."
For many people inside and outside of Europe, it is hard to get beyond the sense of the EU as an organisation stumbling from one crisis to another while meddling in member states' sovereignty. Countries such as Britain, which joined in 1973, now find themselves wondering if it was the right decision.
In their acceptance speech on Monday, Van Rompuy and Barroso will be hoping to overturn those impressions by invoking the despair and misery produced by World War Two and emphasising what Europe and its institutions have done in the decades since to prevent trading partners going to war with each other.
"(This prize) is not only rewarding past achievements, it is also an encouragement to go further and to work further on deepening the European Union," Van Rompuy said. "The answer is more Europe and more integration."