Pope Sergius I was the bishop of Rome from 15 December 687 to his death, and is revered as a saint by the Roman Catholic Church. He was elected at a time when two rivals, Paschal and Theodore, were locked in a dispute about which of them should become pope. His papacy was dominated by his response to the Quinisext Council, the canons of which he steadfastly refused to accept. Thereupon Emperor Justinian II ordered Sergius' arrest, but the Roman people and the Italian militia of the exarch of Ravenna refused to allow the exarch to bring Sergius to Constantinople.
Lamb of God is a title for Jesus that appears in the Gospel of John. It appears at John 1:29, where John the Baptist sees Jesus and exclaims, "Behold the Lamb of God who takes away the sin of the world." It appears again in John 1:36.
Agnus Dei c. 1635–1640, by Francisco de Zurbarán, Prado Museum
Lamb bleeding into the Holy Chalice, carrying the vexillum
Adoration of the Mystic Lamb, with gushing blood, detail of the Ghent Altarpiece, Jan van Eyck, c. 1432
Closeup of the restored Adoration of the Mystic Lamb. The face of the Lamb was painted over with a more animal-like appearance (left). The originally intended version (right) has unusually humanoid features, with distinct ears and forward-facing eyes that appear to look directly at the viewer of the panel.