Seven Ecumenical Councils

• The First Council of Nicea, AD 325
  Rejected Arianism and adopted the original Nicene Creed, fixed Easter date; recognized primacy of the sees of Rome, Alexandria and Antioch and granted the See of Jerusalem a position of honor.
  
  
• First Council of Constantinople, AD 381
  Rejected Arianism and Macedonianism, revised the Nicene Creed in regard to the Holy Spirit
  
  
• Council of Ephesus, AD 431
  Rejected Nestorianism, proclaimed the Virgin Mary as the Theotokos ("God-bearer" or "Mother of God"), repudiated Pelagianism, and reaffirmed the Nicene Creed. This and all following councils are not recognized by the Assyrian Church of the East.
  
  
• Council of Chalcedon, AD 451
  Rejected the Eutychian doctrine of monophysitism, adopted the Chalcedonian Creed, which described the hypostatic union of the two natures of Christ, human and divine. Reinstated those deposed in 449 and deposed Dioscorus of Alexandria. Elevation of the bishoprics of Constantinople and Jerusalem to the status of patriarchates. This and all following councils are rejected by the Oriental Orthodoxy.
  
  
• Second Council of Constantinople, AD 553
  Rejected the Three Chapters as Nestorian, condemned Origen of Alexandria, decreed Theopaschite Formula (“God suffered in the flesh”).
  
  
• Third Council of Constantinople, AD 680-681
  Rejected Monothelitism and Monoenergism.
  
  
• Second Council of Nicaea, AD 787
  Rejected the veneration of icons (condemned at the Council of Hieria, 754) and repudiated iconoclasm. This council is rejected by some Protestant denominations, which condemned the veneration of icons.

Roman Catholic Councils

• Fourth Council of Constantinople, AD 869-870
  Deposed Patriarch Photios I of Constantinople as an usurper and reinstated his predecessor Saint Ignatius. Photius had already been declared deposed by the Pope, an act which the Church of Constantinople accepted at this council. After the death of Ignatius, Photius was reinstated as Patriarch with papal approval.
  
  
• First Council of the Lateran, AD 1123
  This addressed investment of bishops and the Holy Roman Emperor's role therein.
  
  
• Second Council of the Lateran, AD 1139
  This reaffirmed Lateran I, addressed clerical discipline (dress, marriages).
  
  
•  Third Council of the Lateran, AD 1179
  This restricted papal election to the cardinals, condemned simony, introduced minimum ages for ordination (thirty for bishops).
  
  
• Fourth Council of the Lateran, AD 1215
  This defined transubstantiation, addressed papal primacy and clerical discipline.
  
  
• First Council of Lyon, AD 1245
  This deposed Emperor Frederick II, levy to support the Holy Land.
  
  
• Second Council of Lyon, AD 1274
  This attempted reunion with the Eastern churches, approved Franciscan and Dominican orders, tithe to support crusade, conclave procedures.
  
  
• Council of Vienne, AD 1311-1312
  This disbanded the Knights Templar.
  
  
• Council of Constance, AD 1414-1418
  This solved the Great Western Schism, condemned John Hus, beginnings of conciliarism.
  
  
• Council of Basel, Ferrara and Florence, AD 1431-1445
  This addressed church reform and reunion with the Eastern Churches, split into two parties: The fathers remaining at Basel became the apogee of conciliarism. The fathers at Florence achieved union with various Eastern Churches and temporarily with the Eastern Orthodox Church.
  
  
• Fifth Council of the Lateran, AD 1512-1514
  This addressed church reform.
  
  
• Council of Trent, AD 1545-1563
  This addressed (with interruptions) church reform and repudiated Protestantism, defined role and canon of Scripture, the seven sacraments, strengthened clerical discipline and education. Though temporarily attended by Protestant delegates, this and the following councils are rejected by Protestants.
  
  
• First Vatican Council, AD 1870 (officially, 1870-1960)
  This defined pope's primacy in church governance and his infallibility, repudiated rationalism, materialism and atheism, addressed revelation, interpretation of scripture and the relationship of faith and reason. This and the following councils are rejected by the emerging Old Catholic Church.
  
  
• Second Vatican Council, AD 1962-1965
  This addressed pastoral and disciplinary issues dealing with the Church and its relation to the modern world, including liturgy and ecumenism. This council is rejected by some traditionalists.

Eastern Orthodox Councils

• Fourth Council of Constantinople, AD 879-880
  This restored Photius to the See of Constantinople and condemned the double-procession doctrine concerning the Holy Spirit. Today, this council is accepted by the Eastern Orthodox Church but not regarded as Ecumenical by the Roman Catholic Church.
  
  
• Fifth Council of Constantinople, AD 1341-1351
  This affirmed hesychastic theology according to Gregory Palamas and condemned the Barlaam of Seminara.
  
  
• Synod of Jerusalem, AD 1672
  This defined Orthodoxy relative to Roman Catholicism and Protestantism, defined Biblical canon.