Gregory was born to noble parents, Marcellus and Honesta, around 669. As a very young man, he was brought to the papal court. During the reign of Pope Sergius I (687-701), he served as subdeacon and paymaster/almoner. Later, he became a deacon and was placed in charge of the Vatican library. By the time of Pope Constantine, Gregory was noted for his superior intelligence. He became papal secretary and was the main negotiator in Constantinople for the pope regarding the Quinsext Council documents.
Pope Constantine died April 9, 715. Gregory was quickly elected and consecrated on May 19.
He immediately began the repair of the city walls, requested by Pope Sisinnius several years before. As the repairs were underway, storms and major flooding of the Tiber damaged much in the city in October 716. Gregory ordered litanies to be said for the protection of Rome. The waters stopped at the foot of the Capitoline Hill.
Right away, Gregory had to, once again, defend orthodoxy against monothelitism, the teaching that Christ had one nature.
Finally, in 716, Theodo, Duke of Bavaria, met with Gregory to discuss the continuing Christian conversions. Gregory sent delegates to Bavaria with instructions. His continuing interest in this country lead him to consecrate St. Corbinian Bishop of Freising.
Two years after meeting Theodo, Gregory met with Winfred, the Anglo-Saxon missionary. He changed the priest’s name to Boniface and commissioned him to preach in Germany. Over the years, letters of interest and congratulations were exchanged between the two. By 726, they were discussing new churches being built.
Supporter of the Benedictines, Gregory helped restore Monte Cassino, which had been severely damaged by the Lombards in 584.
The Lombards were still difficult to deal with. Gregory managed to get the Lombard king Liutprand to not retake the Cottian Alps, again. In 717, the Duchy of Benevento captured a key spot cutting Rome off from Naples. Gregory had to fund Duke John I of Naples to retake the town. When the Lombard Duke Faroald II of Spoleto captured the port of Ravenna, Gregory brokered a deal to get it returned. The Lombards continued to take Italian territory in bits. He tried to get the attention of Charles Martel, the Frank ruler, but he had no success. When the iconoclast decrees of the Byzantine emperor occurred in 727, fighting began between the Byzantine forces and the Lombards. Gregory brokered a deal between King Liutprand and the Exarch of Ravenna. In 729, Gregory and Liutprand met and reached a truce, referred to as the Sutri agreement. The towns of Sutri and the hill towns in Latium were given to the Papacy. This was the beginning of the Papal States.
The iconoclast controversy began round 726, when the new emperor, Leo III, demanded that all images of saints be destroyed. He insisted that they cease being venerated. His followers argued a prohibition against venerating images found in the Old Testament. It could lead to idolatry, was the argument. Gregory argued for a symbolic veneration, in much the same way that we are reminded of our loved ones through photographs, nowadays. Gregory persevered in his faith, standing against the Byzantine emperor. He made it a point to counsel the people to be submissive to the authority put over them, however, not to the point of denying their faith. The pope wrote to Emperor Leo III, saying, “I pray God to give you prudence and repentance so that you will return to the truth that you left and bring the people to the bosom of the Catholic Church.” This became one of the largest arguments between Rome and Constantinople, leading, a few centuries later, to a split between the two which has never healed.
Pope Gregory died on February 11, 731 after an exhausting 16 year reign. He is considered a saint in the Church.