His career changed dramatically in 1905, when he was commissioned to write a detective story for the magazine Je sais tout. The result, "The Arrest of Arsène Lupin," introduced the charismatic thief, master of disguise, and occasional detective whose wit, elegance, and audacity captivated readers across the world. Leblanc went on to write dozens of Lupin adventures over nearly three decades.
His major works include Arsène Lupin, Gentleman Burglar (1907), Arsène Lupin versus Herlock Sholmes (1908), The Hollow Needle (1909), 813 (1910), The Crystal Stopper (1913), The Teeth of the Tiger (1917), and The Island of Thirty Coffins (1919). Although Leblanc also wrote psychological and science-fiction novels, Arsène Lupin remains his enduring legacy, inspiring countless adaptations, including films, comics, and the popular Netflix series Lupin (2021).