 The opening address of the 1912 Salon de la Section d'Or—the most important pre-World War I Cubist exhibition—was given by Apollinaire.On 7 September 1911, police arrested and jailed him on suspicion of aiding and abetting the theft of the "Mona Lisa" and a number of Egyptian statuettes from the Louvre, but released him a week later.The theft of the statues was committed by a former secretary of Apollinaire, Honoré Joseph Géry Pieret, who had returned one of the stolen statues to the French newspaper the "Paris-Journal".