This essay shows that deep devotion and material interests were not incompatible for medieval hagiographers. Examination of the vita of Eucharius, first bishop of Trier, written around 900, reveals that its author intended to reinforce the reputation of his church by glorifying the saint. But in those days, Trier was too weak to claim political prerogatives. Only when the context had changed in the second half of the tenth century, could the bishops of Trier successfully use it for political ends. Indeed, the text became a strong argument for Bishop Theoderich of Trier when he obtained the so-called primacy over the churches of Cologne and Mainz in 969.