Art historians have long debated the question why sources about the origin of the Mona Lisa portrait provide conflicting information. This monograph presents a solution for this quandary: these 16th century sources don't agree because they are not talking about the same painting. If we consider this possibility, that Leonardo painted not one, but two versions of the Mona Lisa, then all of these problems begin to resolve themselves. In fact, throughout his life Leonardo would often return to a motif or composition for a variety of reasons. Thus we have at least two versions of The Virgin of the Rocks, painted by Leonardo with the De Predis brothers in Milan, and two versions of the Madonna of the Yarnwinder, painted by Leonardo with his assistants in Florence. In other words, the proposition that Leonardo may have painted not one, but two versions of the Mona Lisa is by no means far-fetched. Nonetheless, it also raises an important question. If Leonardo did paint an earlier version in addition to the Louvre Mona Lisa, where is this portrait today? And how can we determine whether this painting is indeed an autograph, rather than one of the many Mona Lisa versions and copies that are still extant today?The answers to these questions are provided in this book, based on contributions by scholars from around the world. They include Prof. John Asmus of the University of California at San Diego; Prof. Vadim Parfenov at the State Electrotechnical University in St. Petersburg, Russia; Prof. Átila Soares da Costa Filho of the Universidade Cândido Mendes in Rio de Janeiro, Brazil; Prof. Jason Halter of the University of Michigan; and Prof. Robert Meyrick of Aberystwyth University. In addition, this monograph includes contributions by noted art critic Gérard Boudin de l'Arche and two prominent artists, Albert Sauteur and Joe Mullins. The book is edited by Prof. Jean-Pierre Isbouts of Fielding Graduate University at Santa Barbara, CA. His previous publications on Leonardo da Vinci include The Mona Lisa Myth; Young Leonardo: The Evolution of a Revolutionary Artist; and The Da Vinci Legacy, co-authored with Dr. Christopher Brown.