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.
Trafalgar Square Christmas tree is given by the city of Oslo as a token of Norwegian gratitude to the people of London for their assistance during the years 1940-45.<br><br>A tree has been given annually since 1947." The tree lighting ceremony in Trafalgar Square takes place on the first Thursday in December and is attended by thousands of people. The ceremony, led by the Lord Mayor of Westminster, includes a band and choir followed by the switching on of the Christmas lights. Traditionally, the tree provides a focal point for Christmas carolling groups. For many in London, the tree and the accompanying carolling signals the