John Pohl is a research archaeologist at UCLA. He is an eminent authority on American Indian civilizations and has directed numerous archaeological excavations in Mexico, Central America, Canada, and the United States. He has published extensively on subjects ranging from human origins to the rise of the Aztec empire and specializes in the decipherement of ancient pictographic writing systems. Adam Hook studied graphic design at art college and began his illustrating career in 1983. He has worked with a variety of educational publishers covering various subjects within the fields of history and natural history. For Osprey he has illustrated numerous Campaign and Warrior titles. Adam lives and works in Sussex, UK.