The Codex Mendoza is a treasure in the Oxford Library in England. Shortly after the Spanish conquest of the Aztecs the first Viceroy commissioned this book for King Charles V in order for him to become familiar with the people of this new land. It was painted by an Aztec book artist to which a Spanish priest familiar with the Aztec language added notes. This book reproduces all its pages and provides explanations in English. It is a rare insight into the Aztec world.