7 Ecumenical Councils

Point 5 of the Theological Statement of the Anglican Church in North America reads

"Concerning the seven Councils of the undivided Church, we affirm the teaching of the first four Councils and the Christological clarifications of the fifth, sixth and seventh Councils, in so far as they are agreeable to the Holy Scriptures."

The first seven councils have the most relevance to Protestant Christianity. Other subsequent councils are of particular interest only to Roman Catholicism and Eastern Orthodoxy.

First Council of Nicaea, (325): affirmed that Jesus is truly God and equal to the Father; repudiated Arianism, adopted the Nicene Creed.
First Council of Constantinople, (381): affirmed that Jesus was perfectly man against the Apollinarians; revised the Nicene Creed into its present form which is used in the Eastern and Oriental Orthodox churches; prohibited any further alteration of the Creed without the assent of an Ecumenical Council.
Council of Ephesus, (431): affirmed that Jesus is one person against Nestorianism; proclaimed the Virgin Mary as the Mother of God, and also condemned Pelagianism.
Council of Chalcedon, (451): affirmed that in Jesus there are two distinct natures in one person that are hypostatically united "without confusion, change, division or separation"; repudiated the Eutychianism and Monophysitism; adopted the Chalcedonian Creed.
Second Council of Constantinople, (553): reaffirmed decisions and doctrines explicated by previous Councils, condemned new Arian, Nestorian, and Monophysite writings.
Third Council of Constantinople, (680–681): asserted that Jesus had both a divine and human will; repudiated Monothelitism.
Second Council of Nicaea, (787); restoration of the veneration of icons and end of the first iconoclasm. It is rejected by some Protestant denominations, who instead prefer the Council of Hieria (754), which had also described itself as the Seventh Ecumenical Council and had condemned the veneration of icons.

Ordinands are expected to have familiarity with the 7 councils and an understanding of the heresies the church has rejected.