This book aims at presenting military gromatic information from the only extent ancient author writing on those questions, ps. Hyginus (IIIth A.C.) who wrote a work about metatio (land distribution to the troops of the Roman army). Several scholars studied this book until very recently, but generally misunderstood vital points. The present edition an Italian translation mainly studies linguistic questions in order to reassess the debated points: the groma's dispositioning according to the symmetry; the right and left side of a camp's map; the distribution of troops within the camp; the disposition of cohortes legionariae in front and of some troops in the central part of the camp; finally the fortifications in the form of a quarter of a cylinder (claviculae), built out of the wall starting from the jamb of the four doors, and a small excavation next each of them (titulum).The present book studies the original text and meaning of the de metatione castrorum by proposing a new restitution and a critical apparatus, a translation, an exhaustive preface with explanations about linguistic and textual problems, a commentary, a chapter about the historical evolution of the text from the first edition to the present one and by a Tabula discrepantium.