Early Middle Ages

• The Fourth Ecumenical Council (Chalcedon) (8 October – 10 November 451)
• The Monophysite reaction after Chalcedon (451 – mid-6th c. (murder of Proterius – 457))
• The fall of the Western Roman Empire (476)
• Zeno's Henoticon and the Acacian Schism (476–477 (Basiliscus's Encyclical); 482 (Zeno's Henoticon) – 519 (end of the Acacian Schism))
• Boethius: theological treatises, the "Consolation of Philosophy," and his execution (c. 480 – execution in 524/526)
• Benedict of Nursia, Monte Cassino, and his "Rule" (c. 480 (birth) – 525/529 (Monte Cassino))
• The baptism of Clovis and the conversion of the Franks (Christmas 496)
• The appearance of the Pseudo-Dionysian corpus (c. 500)
• The Athanasian Creed (Quicunque vult) (c. 500 (first attestation – Caesarius of Arles, d. 542))
• The Three Chapters controversy and the Fifth Ecumenical Council (Second Constantinople, 553) (518 – 553 (council, 5 May – 2 June 553); acceptance in the West completed by the late 6th c.)
• The reign of Justinian and the reconquest of the West (527–565)
• Justinian's closure of the philosophical school at Athens (529)
• Cassiodorus and the monastery of Vivarium (6th c. (retirement from court – 540))
• Celtic missions: Patrick in Ireland, Columba at Iona, and the spread of private penance (c. 563 (Iona) – 590 (Columbanus's continental mission); practice spread in the 7th–8th c.)
• The rise of Islam and the early Arab conquests (570–632 (life of Muhammad); Arab conquests – 633–711)
• The pontificate of Gregory the Great and the mission of Augustine of Canterbury to England (590–604) (588 (title dispute) – pontificate 590–604 – mission to England 596/597–c. 599 – 607 (title "Universal Bishop"))
• The Third Council of Toledo (589): the conversion of the Visigoths and the filioque (589)
• The Monothelite controversy and the Sixth Ecumenical Council (Third Constantinople, 680–681) (622 (Heraclius's plan) – 638 ("Ekthesis") – 649 (Lateran council) – 680–681 (Sixth Ecumenical Council) – 691/692 (Quinisext Council))
• John of Damascus – the last of the Greek Fathers (3rd quarter of the 7th c. – mid-8th c.)
• The rise of the Carolingians, the Battle of Poitiers, and the "Donation of Pepin" (711–732 (invasion and Battle of Poitiers) – 751–756 (Pepin as king, "Donation of Pepin") – 767, 772–774)
• The missions of Willibrord and Boniface among the Germans (690s – 754)
• The Iconoclast controversy and the Seventh Ecumenical Council (Second Nicaea, 787) (723 (emir Yazid's edict) – 726–730 (Leo III's first edicts) – 754 (council of Hieria) – 787 (Seventh Ecumenical Council at Nicaea))
• Charlemagne: conquests, the Carolingian Renaissance, and the Council of Frankfurt (794) (772–804 (conquests and revival); 794 (Council of Frankfurt); 809 (Council of Aachen on the filioque))
• Coronation of Charlemagne and the Aachen Filioque Dispute (800–809)
• The Second Iconoclasm and the Triumph of Orthodoxy (813–843)
• Carolingian Theological Disputes: the Eucharist, Predestination, and John Scotus Eriugena (818–855)
• The Donation of Constantine and the Pseudo-Isidorian Decretals (mid-9th century)
• The Photian Schism (858–880)
• The Mission of Cyril and Methodius to the Slavs and the Christianization of Bulgaria (862–927)
• The Church in feudal society: bishops as vassals, the Peace of God and the Truce of God (10th–11th centuries) (10th – first half of the 11th century)
• The Cluniac and Gregorian Reform: the Investiture Controversy from Canossa to the Concordat of Worms (909–1122)
• Otto I and the Church Policy of the Holy Roman Empire (936–973)
• Symeon the New Theologian and the Origins of Hesychast Theology (949–1022)
• The Baptism of Rus (c. 950–11th century)
• Berengar of Tours and the Eucharistic Controversy (1003–1079)
• The Cathars (Albigensians), the Albigensian Crusade, and the Founding of the Papal Inquisition (11th century–1231)