588 (title dispute) – pontificate 590–604 – mission to England 596/597–c. 599 – 607 (title "Universal Bishop")

The pontificate of Gregory the Great and the mission of Augustine of Canterbury to England (590–604)

Gregory was a Roman aristocrat, a former prefect of Rome, and a monk. In 590, during a plague, he was elected pope against his will. He is generally regarded as the last of the fathers of the ancient Church and the first pope in the modern sense.

Gregory filled the vacuum of civil authority left by the collapse of the Western empire. He organized the grain supply of Rome, restored its fortifications, and made peace with the Lombards. In effect he became ruler of the church lands, "the patrimony of St. Peter".

Already in 588 he and Pope Pelagius II had protested in vain against the Patriarch of Constantinople's adoption of the title "Universal". Yet in 607 that very title ("Universal Bishop") was granted to his own successor, Boniface III. This event is traditionally seen as the beginning of the papacy.

Theologically, Gregory softened and simplified Augustine's teaching. He developed the doctrine of purgatory and is called its "inventor". He also developed the doctrine of the Mass as a sacrifice and of the basic elements of penitential practice: contrition, confession, satisfaction. His influence on medieval Western theology was defining.

In 596/597 he sent a mission to Britain led by the monk Augustine. Augustine landed in Kent and converted King Ethelbert, who was married to a Frankish Christian. He became the first Archbishop of Canterbury, making Canterbury the spiritual capital of England. Negotiations with the Celtic Christians over recognizing Rome's authority (602–603), however, came to nothing.