This book was first written in Latin in 1241 by Frederick II of Hohenstaufen, Holy Roman Emperor (1196-1250). It was first published as a two volume work by his son Manfred. The original is in the Vatican. Next it was published in French in 1300 in six volumes by Jean II of Dampierre. The six volume work was translated into English and combined into one book in 1931 by Dr. Casey Albert Wood (1856-1942), a Canadian ophthalmologist specializing in the eyes of birds, and F. Marjorie Fyfe. The illustrations in this book were obtained in the Vatican Library during the years that Dr. Wood was studying there. Falcons have the best eyesight of any creature known to exist. It has long been recognized that birds of this type have exceptional ability in eyesight. We even have the expression "Eagle-eyed", meaning a person who is alert and can see well. Second is that they are the fastest creature known to exist. Consider the fact that Falcons fly high in the sky, thousands of feet up, yet they can spot a mouse on the ground and dive down to catch him. Dr. Casey Wood was studying falcons to find out why they are able to see so much better than we humans can. One of the very few rare copies of this book known to exist are in the Vatican Library in Vatican City, where he was studying.