Trafalgar Square Authority in conjunction with the charity Unicef, who began ticketing the event to control crowd numbers. A Christmas ceremony has been held in the square every year since 1947. A Norway spruce (or sometimes a fir) is presented by Norway's capital city, Oslo as London's Christmas tree, a token of gratitude for Britain's support during World War II. (Besides war-time support, Norway's Prince Olav and the country's government lived in exile in London throughout the war.) The Christmas tree is decorated with lights that are switched on at a seasonal ceremony. It is usually held twelve days before Christmas Day.
Christmas tree origins are sometimes associated with Protestant Christian reformer Martin Luther, who is said to have first added lighted candles to an evergreen tree. The first recorded Christmas tree can be found on the keystone sculpture of a private home in Turckheim, Alsace (then part of Germany, today France), dating 1576. While today the Christmas tree is a recognized symbol for the holidays, it was once a pagan tradition unassociated with Christmas traditions. Modern Christmas trees have been related to the "tree of paradise" of medieval mystery plays that were given on 24 December, the commemoration and name day of Adam