DateNameMajor DecisionsHeresies AddressedAD 325Nicaea I

Composed the Nicene Creed
Affirmed that Jesus is divine—consubstantial (homoousios) with the Father
Set the date for Easter

Arianism

AD 381Constantinople I

Finalized the Nicene Creed
Finalized the language used for the Trinity: three persons (hypostases); one nature, substance, essence
Affirmed the divinity of the Holy Spirit

Eunomianism
Apollinarianism
Pneumatomachianism (Macedonianism)
Modalism (Sabellianism)

AD 431Ephesus

Affirmed Mary as the Mother of God (Theotokos)

Nestorianism

AD 451Chalcedon

Affirmed that Jesus is one person having two natures (divine and human)

Monophysitism

AD 553Constantinople II

Confirmed that the one person of Jesus is the second Person of the Trinity
Affirmed Mary as perpetual virgin
Confirmed that Jesus, the divine Person of God the Son, truly suffered and died for us in the flesh

Nestorianism
Monophysitism

AD 680-681Constantinople III

Affirmed Jesus has two wills, human and divine

Monothelitism
Monoenergism

AD 787Nicaea II

Affirmed the veneration of sacred images

Iconoclasm

AD 869-870Constantinople IV

Deposed Photius and reinstated Ignatius as the legitimate Patriarch of Constantinople
Affirmed each human person possesses a single rational soul

AD 1123Lateran I (not cited in the Catechism)

Ended the lay investiture of bishops (disciplinary decision)

AD 1139Lateran II (not cited in the Catechism)

Formalized the discipline of priestly celibacy for the Western Church (disciplinary decision)

AD 1179Lateran III (not cited in the Catechism)

Established papal election by the college of cardinals (disciplinary decision)

AD 1215Lateran IV

Affirmed “transubstantiation” to describe the change in the Eucharist during Mass

Catharism (Albigensianism)
Waldensianism
Teachings of Joachim of Fiore

AD 1245Lyons I (not cited in the Catechism)

Deposed the Holy Roman Emperor Frederick II (disciplinary decision)

AD 1274Lyons II

Affirmed the doctrines of purgatory, hell, and final judgment

AD 1311-1312Vienne

Affirmed that the soul is the “form” of the body
Suppressed the Knights Templars
Issued decrees on the reform of morals
Reformed the discipline of poverty for religious life

Free Spiritualism

AD 1414-1418Constance

Ended the Great Western Schism
Affirmed the authority and necessity of the Church and the Pope
Affirmed the Real Presence of Christ in the Eucharist
Affirmed that sacraments administered by clerics in a state of mortal sin are valid

Donatism
Teachings of John Wycliffe
Teachings of Jan Hus

AD 1439-1445Florence

Affirmed that the Holy Spirit proceeds from the Father and the Son (Filioque)
Affirmed the existence of purgatory and hell
Affirmed the seven sacraments are instruments of grace
Affirmed papal primacy
Attempted to restore union with Eastern Orthodox Christians

Conciliarism

AD 1512-1517Lateran V

Affirmed the immortality of the human soul
Condemned usurious practices

Latin Averroism
Gallicanism
Conciliarism

AD 1545-1563Trent

Reaffirmed the word “transubstantiation” to describe the consecration of Holy Communion
Clarified the Church’s teachings on salvation and the sacraments in response to the Protestant Reformers
Reformed the practices of the Church in light of the criticisms of the Protestant Reformers
Established the seminary system for the training of priests
Standardized the liturgy with the publication of a missal, breviary, and ritual
Published a universal catechism to instruct the clergy and the faithful in Catholic doctrine

Sola Scriptura
Sola fide
Pelagianism
Semi-Pelagianism
Conciliarism
Double predestination
Antinomianism

AD 1869-1870Vatican I

Explained the Catholic understanding of the relationship between faith and reason
Affirmed the infallibility and universal, ordinary jurisdiction of the pope

Conciliarism

AD 1962-1965Vatican II

Proclaimed the liturgy as the summit of the Church’s activity and provided for a more conscious and active participation of the laity
Provided for the study of Sacred Scripture and encouraged Catholics to incorporate Scripture into their spiritual lives
Examined the role of the Church in bringing the message of Christ to the modern world
Discussed the Church as the People of God, the role of the laity, and the universal call to holiness