Legend holds that the associated pair of martyrs, Carpophorus and Fidelis, were members of the Theban Legion, whose relics were transferred to Arona during a time of war between Milan and Como.
Goffredo da Bussero (1220-1289 ca.), discussing a group of martyrs of the Theban Legion killed in Lombard territory, states: sed horum duo corpora ad monasterium de Arona dati sunt.