What you should know about the Nobel Peace Prize

The prize is decided by the five-member Norwegian Nobel Committee, led by Thorbjoern Jagland, a former prime minister and the head of the Council of Europe. Committee members are elected by Norway's parliament, and generally represent the entire political spectrum.

There were 231 nominations for the 2012 prize, including 43 organisations, down from last year's record 247 nominations. The committee usually narrows its list to between 25 and 35 names at its first meeting, then to about five or seven by April. The final decision is made about two weeks before the announcement.

The Nobel Peace Prize has been awarded 92 times since 1901, to 101 individuals and 20 organisations. The International Committee of the Red Cross has won the prize three times and the Office of the UN High Commissioner for Refugees twice.

Only 15 women have been awarded the peace prize.

Yemeni journalist Tawakkol Karman was only 32 when she shared the 2011 prize, the youngest ever laureate.

The Vietnamese politician Le Duc Tho is the only person to have refused the prize. He was awarded it in 1973 jointly with US Secretary of State Henry Kissinger for negotiating the Vietnam peace accord. Kissinger never travelled to Oslo to deliver his acceptance speech.

Both Josef Stalin and Adolf Hitler were nominated for the prize - Stalin in 1945 and 1948 for his efforts to end World War Two and Hitler in 1939, although the nomination was never intended to be taken seriously.