The peace prize was given to the EU "for over six decades contributed to the advancement of peace and reconciliation, democracy and human rights in Europe," according to the award committee.
Many complained about the choice, as the European Union was dealing with several pressing economic problems, including the Greek debt crisis, and because several European countries make and sell weapons.
"Alfred Nobel said that the prize should be given to those who worked for disarmament," said Elsa-Britt Enger, a representative of Grandmothers for Peace, in a Reuters report at the time. "The EU doesn't do that. It is one of the biggest weapons producers in the world."
Other critics included former winners of the prize. Archbishop Desmond Tutu, Northern Ireland's Mairead Maguire and Argentina's Adolfo Perez Esquivel, signed an open letter criticizing the decision and said the EU is "clearly not one of the 'champions of peace' Alfred Nobel had in mind" when he created the prize, the Associated Press reported.