The island of Sant’ Andrea, situated on the road that since ancient times has linked the Adige Valley with the Lake Garda, once rose impressively from the green expanse of water, but now is a small hump on the edge of a vast marshy basin. Fifteen centuries ago it was the fortified seat of a contingent of soldiers and their families. In 1998, after a long series of sporadic discoveries that started way back in the 19th century, the Archeaology Section of the Rovereto Civic Museum began a research and study project that involved a series of summer excavations, that brought to light a multi-layered archeological site with finds ranging from the prehistoric age to late antiquity, medieval times and right through to even the First World War. Along the northeastern side and the southern edge of the island the remains have been found of some buildings that can be traced to a fortified settlement and on the top part of the hump the remains of a Romanesque church have been investigated. The buildings that made up the settlement illustrate a complex series of construction periods; so far these have been dated between the 5th and 7th centuries. Numerous examples of armoury and military clothing have been found in the settlement area and this clearly suggests the military function of the site. The volume is devoted to the results of the research in the castrum: A general overview of the site is followed by a part devoted to periodization and stratigraphic analysis of the dig; then there is a large section that includes contributions on the small finds; the fourth part contains some concluding remarks.