Baring-Gould’s sources: Roman Martyrology, and those of Usuardus, Ado, Notker and that attributed to Bede, also the later ones of Maurolycus, Bellinus and Galesinius, sometimes also on Feb. 18. Authority, the contemporary Epistle of the Church of Smyrna to the Church of Pontus, describing the martyrdom of SS. Germanicus, Polycarp, and others; quoted by Eusebius, lib. IV. c. 15.

The Epistle of the Church of Smyrna, narrating its sufferings under the Emperors Marcus Antoninus [Antoninus Pius, Roman emperor 138–161] and Lucius Aurelius, says:—"Germanicus, a noble youth, was particularly pre-eminent as a martyr, for, strengthened by divine grace, he overcame the natural dread of death implanted in us; although the pro-consul was desirous of persuading him, and urged him from consideration of his youth, that, as he was so young and blooming, he should take compassion on himself. He, however, hesitated not, but eagerly irritated the wild beast let loose upon him, that he might be the sooner freed from this unjust and lawless generation."

The Acts of this martyr have been lost.