Who was the first poet in human history? What is the secret of Gioconda's smile? Who is depicted in the center of the Sistine Chapel? What do the words “Horse! Horse! The whole kingdom is for the horse!”? How did Andrei Rublev sign “Trinity”? What does Caravaggio’s “Lute Player” sing? You will find answers to these and many other questions in Alexander Shapiro’s book “Riddles of the Old Masters.”