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.
Aristotelous Square Following Greek traditions, apart from a Christmas tree, the municipality of Thessaloniki also decorates a giant "Christmas ship", which is a Greek variant of the custom of decorating a Christmas tree. Both the Christmas tree and the Christmas boat are over 20 meters tall and are considered a tourist attraction for visitors to the city at the time they are up. Since its creation, the square has been used for a number of important party rallies. Many former Prime Ministers of Greece have given their main address from Aristotelous Square, including Andreas Papandreou, Costas Karamanlis and George Papandreou. Apart from