Born in Siena on 25 February 1964, FABRIZIO CASPRINI is an ophthalmologist surgeon, while MARCO SALIOLA, who was born in Rome on 12 February 1962, is an architect. The pair are researchers who have worked together for many years on the study of the ancient Roman world, focusing on the military aspects of that period, in particular fighting techniques and weapons. Their work is based strictly on scientific principles, and they have become widely acknowledge as experts in their field. Their previous book, Pugio Gladius Breviest, was published in both Italian and English. They often hold conferences in Italy and arrange expositions on Roman military weapons and warfare.