I. The Early Councils (Foundations of Orthodoxy)

• Nicaea I (325)

• Constantinople I (381)

• Ephesus (431)

• Chalcedon (451)

• Constantinople II (553)

• Constantinople III (680–681)

• Nicaea II (787)

(You could frame this section as “Defining Christ and the Trinity” — since that’s what the first seven Councils are about.)

II. The Middle Councils (Christendom & Authority)

• Constantinople IV (869–870)

• Lateran I (1123)

• Lateran II (1139)

• Lateran III (1179)

• Lateran IV (1215)

(Here the tone shifts toward discipline, governance, and sharpening the Church’s universal mission.)

III. The High Medieval & Early Modern Councils (Defense & Reform)

• Lyons I (1245)

• Lyons II (1274)

• Vienne (1311–1312)

• Constance (1414–1418)

• Florence (1431–1449)

• Lateran V (1512–1517)

• Trent (1545–1563)

(This is the golden thread of Catholic response to crisis — East/West schism, reform, Protestant revolt.)

IV. The Last Great Council

• Vatican I (1869–1870)

(You could isolate this as a capstone, since Vatican I defined papal infallibility and closed the authentic conciliar tradition.)

V. The Creeds (Profession of the Faith)

Here you might not want to bury them inside the conciliar timeline — instead, elevate them as a distinct category that flows from the Councils but stands on its own. For instance:

• Apostles’ Creed (used in baptismal context, Roman origin)

• Nicene-Constantinopolitan Creed (325/381, liturgical use)

• Athanasian Creed (Quicumque vult, doctrinal clarity)

• Roman Creed / Old Roman Symbol

• Other local baptismal symbols (Gallican, etc.)

You could order them by:

1. Origins (Apostles’ / Old Roman → Nicene → Athanasian).

2. Use (Baptismal, Liturgical, Doctrinal/Apologetic).

3. Relation to Councils (e.g., Nicene Creed explicitly tied to Nicaea/Constantinople).