Gennadius was a monk and subsequently abbot of the Spanish monastery of San Pedro de Montes at Vierzo. Thereafter he was consecrated bishop of Astorga. Gennadius served in the episcopate for about thirty-five years before resigning his office to spend the end of his life at the Vierzo monastery. He was remembered for his deep piety and for his total dedication to serving God and saving souls. In a will he composed in 915, Gennadius petitions the Apostle Saint Peter, patron of the Vierzo monastery, in these words: "And therefore, until the Shepherd of shepherds shall have appeared, until he shall have come in the glory of majesty...I beseech that you shall intercede to the perfect King, that mercy may excel judgment, and I may be carried over from the left hand and the goats, to the flocks at the right, clothed in the fleece of the Lamb." Over the centuries, Gennadius has been invoked by those suffering from fevers.
