Pope Gregory I, commonly known as Saint Gregory the Great, was the 64th Bishop of Rome from 3 September 590 to his death. He is known for instituting the first recorded large-scale mission from Rome, the Gregorian mission, to convert the then largely pagan Anglo-Saxons to Christianity. Gregory is also well known for his writings, which were more prolific than those of any of his predecessors as pope. The epithet Saint Gregory the Dialogist has been attached to him in Eastern Christianity because of his Dialogues. English translations of Eastern texts sometimes list him as Gregory "Dialogos" from the Greek διάλογος, or the Anglo-Latinate equivalent "Dialogus".

The pope, also known as the supreme pontiff, Roman pontiff or sovereign pontiff, is the bishop of Rome, visible head of the worldwide Catholic Church, and has also served as the head of state or sovereign of the Papal States and later the Vatican City State since the eighth century. From a Catholic viewpoint, the primacy of the bishop of Rome is largely derived from his role as the apostolic successor to Saint Peter, to whom primacy was conferred by Jesus, who gave Peter the Keys of Heaven and the powers of "binding and loosing", naming him as the "rock" upon which the Church would be built. The current pope is Francis, who was elected on 13 March 2013.