One of the most important bishops of Rome and most influential writers of the Middle Ages, Gregory the First is one of only two popes (the other being Leo the First), to have been given the epithet “the Great.”
Perhaps best known for being credited with the compilation of the canon of what is now known (after him) as “Gregorian chant” – that is to say, monastic plainchant, for the Holy Eucharist (the Mass) and the Daily Office – as well as reforms to the Roman liturgy; although as this account notes,
“His role in the development of the Roman liturgy and its chant was considerable, though disputed. He certainly modified various minor features and composed a number of prayers which formed the nucleus of the Gregorian Sacramentary, though this work reached its final form after his death. Many prayers in the sacramentary, if not actually written by him, were inspired by his through and phraseology. Since the tenth century his name has been associated with ‘Gregorian’ chant: while the chant bearing his name arose from a later Carolingian synthesis of Gallican and Roman chant, he probably played a role in the gradual codification and adaptation of several preexisting forms of plainsong.”
Not only chant is known by his name: Gregory’s influence on the Roman liturgy is such that the traditional Roman Catholic Eucharistic canon is frequently known as the “Gregorian Canon,” and our Western Rite Orthodox brothers and sisters call the form of their liturgy based on it “the Liturgy of St. Gregory.”
His primary significance for Anglicans, however, lies in his role as “Apostle to the English”:
“Apparently convinced that the future of Christianity lay with monasticism and not with the declining Eastern Roman Empire, he hoped to lead a group of missionaries in taking the Gospel to the Anglo-Saxons in Britain, after seeing English children or youth on sale as slaves in the Roman market around the year 573. He is said to have remarked on their beauty as being like that of angels, whereupon he was told that they were in fact Angles – causing him to say, Non Angli, sed angeli: “Not Angles, but angels.” But this was not to be his ministry…
Nevertheless, “One of Gregory’s most notable achievements was the conversion of the Anglo-Saxons. He personally took the lead in the whole process, sending Augustine, prior of his own monastery of Saint Andrew’s on the Caelian Hill, and a number of fellow monks to southeastern Britain, to the Jutish kingdom of Kent, where they achieved within a few years the conversion of the people and of their king, Ethelbert. Gregory continue personally to guide the mission in matters that perplexed Augustine by sending a supporting group of missionaries, along with liturgical vessels, books, and vestments, in 601; and by writing to Ethelbert and his Christian queen, Bertha on various matters.
“The close relationship between Rome and the English Church was continued by Gregory’s successors, and in many ways the Church in England was closer to the papacy than the Church in Gaul was. The first Life of Gregory was written in England, and from the biographies written by the Venerable Bede, Aldhelm, and the anonymous biographer of Whitby come eulogies of Gregory as ‘the apostle of the English,’ ‘our father and apostle in Christ,’ and ‘he from whom we have received the Christian faith, he who will present the English people to the Lord on the Day of Judgment as their teacher and apostle.'”