• The Early Councils

• The Middle Councils

• High Medieval Councils

• Early Modern Councils

• The Last Great Council

• The Creeds · Profession of the Faith

“O Timothy, keep that which is committed to thy trust, avoiding the profane novelties of words, and oppositions of knowledge falsely so called.”

"Begotten, not made, being of one substance with the Father."

Nicæa I AD 325

"If anyone does not confess that Emmanuel is God in truth, and therefore that the Holy Virgin is the Mother of God (for she bore in a fleshly way the Word of God become flesh), let him be anathema."

Ephesus AD 431

“Peter has spoken through Leo!”

Chalcedon AD 451

An Ecumenical Council is the most solemn and authoritative assembly of the teaching Church (Magisterium), gathering the Bishops from the entire world under the headship of the Roman Pontiff, the Vicar of Christ, to deliberate, legislate, and define matters of faith and morals for all Catholics.

These Councils are instituted to address and extinguish spreading errors, to clarify and define necessary doctrines, to safeguard discipline, and to strengthen Christian piety, acting as the chief instrument through which the Holy Spirit maintains the infallible Truth of the Church against infiltration and heresy throughout the ages.

The decrees of an Ecumenical Council, once confirmed by the successor of Saint Peter (the Pope), bind the consciences of all the faithful, serving as permanent, unchangeable monuments of orthodox teaching that ensure the continuity and integrity of the sacred deposit of Faith given by Our Lord to His Apostles.

The faithful Catholic must recognize that the Holy Spirit, promised by Our Lord, has perpetually guided the Church to preserve the sacred deposit of Faith, most especially through the Ecumenical Councils. Following the persecutions of the early centuries, the rise of impious heretics, those enemies of Christ who sought to corrupt the divine truths, necessitated these solemn assemblies of bishops, who, gathered under the guidance of the Holy See, acted as the definitive and infallible voice of the Church.

From the First Council of Nicæa (325 A.D.) to the Second Council of Nicæa (787 A.D.), these early venerable Councils established the foundation of Christology by defining the true nature of the Most Holy Trinity and the Person of Jesus Christ. These decrees serve as the immovable bulwarks against all doctrinal error, ensuring that the flock remains securely within the boundaries of Truth, and demonstrating the Church's constant, supernatural protection against the gates of hell.

The early Councils acted as the unshakeable pillars of the Catholic Creed, decisively confronting and condemning those who sought to dismantle the core mysteries of salvation. The Councils of Nicæa I (325 A.D.), Constantinople I (381 A.D.), and Ephesus (431 A.D.) established the essential doctrines concerning the Godhead, clarifying the divinity of the Son against the heresy of Arius (Arianism) and defining Our Lady as the Theotokos (Mother of God) against the heresy of Nestorius (Nestorianism).

The subsequent Councils of Chalcedon (451 A.D.), Constantinople II (553 A.D.), and Constantinople III (680-681 A.D.) firmly defined the two natures (divine and human) and the two wills in the Person of Jesus Christ, that is, perfect God and perfect man, against the Monophysite and Monothelite heresies, thus safeguarding the full reality of the Redemption.

Finally, the Second Council of Nicæa (787 A.D.) defended the pious and ancient practice of venerating sacred images, asserting that the honor paid to the image passes to the prototype, thereby confirming the sacramental and visible nature of the Faith against the wicked and depraved Iconoclasts, and setting a precedent against later Iconoclasm. To accept the teachings of these Councils is to accept the entirety of the revealed Faith.