On this day, French poet Guillaume Apollinaire is arrested and jailed on suspicion of stealing Leonardo da Vinci’s Mona Lisa from the Louvre museum in Paris. The 31-year-old poet was known for his radical views and support for extreme avant-garde art movements, but his origins were shrouded in mystery. Today, it is believed he was born in Rome and raised in Italy. He appeared in Paris at age 20 and quickly mixed into the city’s bohemian set. His first volume of poetry, The Rotting Magician, appeared in 1909, followed by a story collection in 1910. A supporter of Cubism, he published a book about the subject, Cubist Painters, in 1913. The same year, he published his most esteemed work, Alcools, where he used a variety of poetic forms and traditions to capture everyday street speech. In 1917, his experimental play The Breasts of Tiresias was produced, for which he coined the term “surrealist.” Apollinaire’s mysterious background and radical views led authorities to view him as a dangerous foreigner and prime suspect in the Mona Lisa heist, which took place August 22. No evidence surfaced, and Apollinaire was released after five days. Two years later, a former employee of the Louvre, Vincenzo Perggia, was arrested while trying to sell the famous painting to an art dealer.