Consequently, very little can be said about the historical individual. The historical evidence is found in records of a priest Hatto, towards the end of the 9th century. He made an inventory of the abandoned monastery from fear of the Normans. His list includes a Codex edged with silver and ivory, containing the Vitae of St. Fridolin, St. Hilarius, and St. Arnulphus. Fridolin appears to have been an Irish missionary among the Alamanni along the Upper Rhine, who at the time were under Merovingian rule, and he went on to found Säckingen Abbey.