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 construction started, impeding its progress. The square was to be named for William IV commemorating his ascent to the throne in 1830. Around 1835, it was decided that the square would be named after the Battle of Trafalgar as suggested by architect George Ledwell Taylor, commemorating Nelson's victory over the French and Spanish in 1805 during the Napoleonic Wars. After the clearance, development progressed slowly. The National Gallery was built on the north side between 1832 and 1838 to a design by William Wilkins, and in 1837 the Treasury approved Wilkins' plan for the laying out of the square, but