Fidelis was born in the town of Sigmaringen in Germany in the year 1578. He joined the Order of Friars Minor Capuchin and lived an austere life in vigils and prayers. He was indefatigable in preaching the word of God, and at the commsand of the Sacred Congregation for the Propagation of the Faith the preached sound doctrine in Raetia. In the year 1622 he was attached by heretics at Sewis in Switzerland and died as a martyr.
From the common of one martyr, in the Easter Season, 1414, or of pastors, 1426.