John Langdon (typographer) Langdon is known mostly through his association with Dan Brown, and the novels "Angels & Demons", "The Da Vinci Code," "The Lost Symbol, Inferno, and Origin". The protagonist of these novels was named Robert Langdon as a tribute to John Langdon, and he will continue to be so for his next 12 books, an estimate given by Dan Brown himself. Langdon is now a professor of typography and corporate identity at Drexel University in Philadelphia. He continues to do work on ambigrams, as well and fine art works that incorporate language, type, and philosophy. Langdon credits his paternal grandparents for
Robert Langdon from him. While he is in the Louvre, he meets Sophie Neveu, a young cryptologist from the DCPJ. When Langdon and Sophie get the chance to talk in private, he finds out that Jacques Saunière is her grandfather. Saunière instructs Sophie to 'find Robert Langdon', according to the message he left for her in the floor. Hence, Sophie believes he is innocent of her grandfather's murder. He spends the rest of the novel dodging the police and trying to solve the mystery of an ancient secret society, the Priory of Sion, which was once headed by Leonardo da Vinci. At