St Germanus was the son of a senator of Constantinople, was educated for the priesthood, and was for some time attached to the metropolitan church; but after his father's death, a date which is not recorded, he was appointed bishop of Cyzicus. Under Anastasius II Germanus was translated from Cyzicus to the see of Constantinople. Within a year of his accession he called a synod for 100 bishops at which the true doctrine of the Church was asserted against the monothelite heresy.
After Leo the Isaurian had ascended the imperial throne in 717, St Germanus crowned him in the church of the Holy Wisdom, and the emperor solemnly swore to preserve the Catholic faith. Ten years later, when Leo declared himself in sympathy with the iconoclasts and set himself against the veneration of images, St Germanus reminded him of the vow he had made. In spite of this remonstrance, the emperor issued an edict prohibiting the outward display of reverence to religious statues and pictures, all of which were to be raised to a height which precluded the public from kissing them. A later and still more drastic decree ordered the general destruction of sacred images and the whitewashing of church walls. The patriarch, though a very old man, spoke out fearlessly in defense of the images and wrote letters upholding the Catholic tradition to bishops inclined to favor the iconoclasts.
Over and over again did Leo attempt to win over the aged prelate, but finally in 730, realizing that his efforts remained fruitless, he practically compelled St Germanus to relinquish his office. The saint then retired to his paternal home, where he spent the remainder of his life in monastic seclusion, preparing for his death which took place when he was over ninety.
From Butler's LIVES OF THE SAINTS, HarperOne, 1956, p. 142 (originally published in 1756-9)