The Norwegian prize committee said the EU received the award for six decades of contributions "to the advancement of peace and reconciliation, democracy and human rights in Europe.

"The stabilizing part played by the European Union has helped to transform a once torn Europe from a continent of war to a continent of peace,'' Nobel committee chairman Thorbjoern Jagland said.

The EU rose from the ashes of World War II, born of the conviction that ever-closer economic ties would make sure that century-old enemies never turned on each other again. It's now made up of 500 million people in 27 nations, with other nations lined up, waiting to join.

The idea of a united Europe began to take on a more defined shape when, on May 9, 1950, French Foreign Minister Robert Schuman proposed that France and the Federal Republic of Germany pool their coal and steel resources in a new organization that other European countries could join.

"Today war between Germany and France is unthinkable. This shows how, through well-aimed efforts and by building up mutual confidence, historical enemies can become close partners,'' the committee said.

The citation also noted the democratic conditions the EU has demanded of all those nations waiting to join, referred to Greece and Spain when they joined the 1980, and to the countries in Eastern Europe who sought EU membership after the 1989 fall of the Berlin Wall.

The prize focused on the EU's historical role as a builder of peace at a time when the union's existence is under challenge from the financial crisis that has stirred deep tensions between north and south and when there are questions about the form in which the EU will survive.

"The EU is currently undergoing grave economic difficulties and considerable social unrest,'' Jagland said. "The Norwegian Nobel Committee wishes to focus on what it sees as the EU's most important result: the successful struggle for peace and reconciliation and for democracy and human rights.

"The stabilizing part played by the EU has helped to transform most of Europe from a continent of war to a continent of peace.''