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 this has happened in the long history of Europe," said Herman Van Rompuy, president of the European Council, who collected the prize along with European Commission President Jose Manuel Barroso and Martin Schulz, president of the European Parliament. "The facts prove the European Union is a peacekeeping instrument of the first order."
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 could not decide who should accept the award or who specifically was to be honoured.
In the end it was decided the prize was for all Euro-peans, to be picked up by the heads of the three main EU institutions. Twenty EU leaders also chose to attend the ceremony, but Prime Minister David Cameron, whose relationship with Brussels is tense, stayed away. And Mr Tutu, who fought the apartheid system in his native South Africa, said last week the EU did not deserve the award.
On Sunday members of left-wing and human-rights groups marched through 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 the prize should be given to those who worked for dis-armament," said Elsa-Britt Enger, 70, from Grand-mothers for Peace.
"The EU doesn't do that. It is one of the biggest weapons producers in the world."