The "Life" of Saint Germanus is recounted in the eleventh-century "Passio sancti Germani", which appears in the Vitae et passiones diversorum sanctorum.

[3] The manuscript of the Vitae is preserved as the Codex Sangallensis 551 ('Codex of Saint-Gall' 551), housed in the Abbey library of Saint Gall.

Driven by a desire for greater perfection, he left with his brother and some religious for Luxeuil, where Abbot Waldebert received him, conferred on him the priesthood, then around 640 sent him, to organize and govern the monastery of Granfeld (Monasterium Grandis Vallis) or Moutier-Granval, recently founded by Gundoin, Duke of Alsace.

[7] According to legend, Gundoin's successor, Boniface, Duke of Alsace had trouble keeping the people of the Sornegau from revolting.

The situation became worse under his successor Adalrich, Duke of Alsace (known as "Eticho"), who wanted to subdue the area around Delémont.

The progress of Protestantism and a fire at the abbey which had become a collegiate church, of which nothing remains, led the canons to withdraw and transport the relics of the two saints to Délémont in the canton of Jura, where they continue to be venerated.