After the Emperor Constantine began the process of tolerating then adopting Christianity, councils flourished.  The Council of Nicaea is the first Ecumenical (universal) council.  The first four ecumenical councils,  were given a special place in the traditions of the church. 

Constantine and the Council of Nicaea (325)   Caesaropapism

Tanner Texts and Translations

Constantinople  I (381)

Ephesus (431)

Chalcedon (451)

Constantinople II (553)

Constantinople III (680-681)

Nicaea II (787)

Constantinople IV (869-870)

Decrees of the Ecumenical Councils, 1: Nicaea I-Lateran V, 2: Trent-Vatican II, ed. Norman P. Tanner. 2 Volumes. London-Washington, D.C.: Sheed & Ward and Georgetown University Press, 1990 (Greek-Latin texts with facing English translation)  

Western Councils

Council of Arles 314 Called by Constantine --- Letter and canons sent to Pope Silvester

Council of Cologne 346  Trial of Eufrata, who had denied Christ was God (Eufrata Christum Deum negat)
Council of Valence 374 Ecclesiastical discipline

Pope Gregory the Great (590-604) compared the first four councils to the four Gospels.  From the mid-fifth century, the papacy claimed the right to approve the acts of councils.  The first eight Ecumenical Councils were held in the Greek speaking Mediterranean.