Pentecost commemorates the descent of the Holy Spirit upon the apostles fifty days after Easter (Acts 2:1-41). The name derives from the Greek pentekostos, 'fiftieth,' referring to the Jewish festival of Shavuot (the Feast of Weeks), which falls fifty days after Passover. The typological connection is deliberate and profound: as the Law was given at Sinai fifty days after the Exodus, so the Spirit was given fifty days after the Resurrection, writing the law on human hearts rather than tablets of stone (cf. Jeremiah 31:33, 2 Corinthians 3:3). The Christian observance of Pentecost is among the oldest feasts after Easter itself. Tertullian (De Baptismo 19, c. 200 AD) mentions Pentecost as a season particularly appropriate for baptism, suggesting it was already a significant liturgical occasion by the early third century. The Council of Elvira (c. 305) references the Pentecost season. Eusebius (Vita Constantini 4.64) records that Constantine was baptized at Pentecost. By the fourth century, the feast was universally observed across both East and West. The BCP 2019 lists Pentecost among the seven Principal Feasts — the highest liturgical rank — and the Day of Pentecost is one of the four traditional Ember Day anchors, when prayers are offered for those called to Holy Orders.

Pentecost carries a distinctive liturgical character shaped by its dual identity as both the culmination of Easter and its own feast. The color is red — for the tongues of fire (Acts 2:3) and for the Spirit's presence in the Church. In the medieval West, the custom of releasing doves or dropping rose petals from church ceilings dramatized the Spirit's descent; the French name for Pentecost, Pâques des Roses, recalls this practice. The sequence hymn Veni Sancte Spiritus ('Come, Holy Spirit'), attributed to Stephen Langton (c. 1200), became one of the most beloved Pentecost texts in Western Christianity. In the East, Pentecost is closely linked with the feast of the Holy Trinity, which the Byzantine tradition celebrates on the same day (the West assigns Trinity to the following Sunday). The Kneeling Prayers of Pentecost Vespers in the Byzantine rite mark the formal end of the Paschal season: the congregation kneels for the first time since Easter. The BCP 2019 provides two collects — the first emphasizing the Spirit's revelation of 'the way of eternal life to every race and nation,' the second (from the 1549 BCP) asking for 'a right judgment in all things.' The Old Covenant overlay is significant: Shavuot celebrates both the wheat harvest and the giving of Torah, and the Pentecost narrative in Acts deliberately echoes Sinai imagery — the sound of wind, the appearance of fire, the gathering of nations.

Almost nothing is known of Augustine's life before his mission. He was prior of the monastery of St. Andrew on the Coelian Hill in Rome when Pope Gregory the Great selected him to lead a missionary expedition to Britain in 596. Gregory had long desired to evangelize the Anglo-Saxons — Bede records the tradition that Gregory, seeing fair-haired English slaves in the Roman market, declared them 'not Angles but angels' (non Angli sed Angeli).

The mission nearly collapsed before it began. The monks, intimidated by reports of the ferocity of the Anglo-Saxons and the dangers of the journey, persuaded Augustine to return to Rome and beg release. Gregory refused, sent Augustine back with letters of encouragement and formal authority, and the party finally crossed the Channel in 597, landing on the Isle of Thanet in Kent.

King Æthelberht, though still pagan, received them cautiously — insisting on meeting outdoors, where he believed magic would have less power. Impressed by their sincerity, he granted them a residence in Canterbury and permission to preach. Within a year Æthelberht himself was baptized, and mass conversions followed.

Augustine established his cathedral at Canterbury and was consecrated archbishop by Gallic bishops, receiving the pallium from Gregory. He founded the monastery of Saints Peter and Paul (later St. Augustine's) and consecrated Mellitus as Bishop of London and Justus as Bishop of Rochester.

His efforts to bring the existing British Christian communities into unity with Canterbury were less successful. A conference with British bishops at a location Bede calls 'Augustine's Oak' broke down over disputes about Easter dating and other customs. Augustine died around May 26, 604 or 605.

Traditionally, Augustine's mission was confirmed by miraculous signs. According to Bede, drawing on earlier Canterbury sources, Augustine performed healings that convinced the pagan English of the power of the Christian God. Gregory, writing to Augustine in a letter preserved by Bede (HE I.31), counseled him not to take pride in miracles but to rejoice that his converts' names were written in heaven — a caution that itself confirms miracle claims were circulating during Augustine's lifetime.

Bede also records a story — which he presents cautiously — that when British bishops refused to cooperate with Augustine, the archbishop warned them that they would suffer at the hands of the Saxons, a prophecy connected to the later massacre of the monks of Bangor-Is-Coed by King Æthelfrith of Northumbria (HE II.2). The story serves Bede's narrative purpose of vindicating the Canterbury mission against Celtic resistance, and the prophetic framework should be read with that in mind.