Each year since 1947, a Christmas tree has been given to the people of London from the people of Norway in gratitude for Britain's support for Norway during World War II. The King of Norway went to London after the country was occupied by Germany, and set up a "government in exile" here before returning to his country after the war had ended. The tree is therefore not just a decoration, but a symbol of peace and of friendship. The tree is chosen specially from the forests around Oslo. The Mayor of Westminster travels to Oslo for a ceremony there, after which the tree is carried by road and boat to the centre of London. For many Londoners the Christmas tree and carol singing in Trafalgar Square signal the countdown to Christmas.