Here is a helpful, at least for me, outline of the development of christological articulation through the councils; this is provided by (who else) Thomas F. Torrance:
(i) The Council of Nicaea in AD 325, which affirmed that Jesus Christ is truly (alethos) God, in an affirmation of faith against the Arians.
(ii) The Council of Constantinople in AD 381, which affirmed that Jesus Christ was perfectly (teleos) man, against the Apollinarians whose teaching impaired the perfect humanity of Christ.
(iii) The Council of Ephesus in AD 431, which affirmed that Jesus Christ is one person, against the Nestorians who divided Christ into two persons.
(iv) The Council of Chalcedon in AD 451, which affirmed that in Jesus Christ there are two distinct natures in one person, and that in the one person of Christ they were hypostatically united ‘unconfusedly, incontrovertibly, indivisibly, inseparably’, or ‘without confusion, change, division or separation’. This was affirmed against the Eutychians and Monophysites.
(v) The Council of Constantinople AD 680, which asserted that Jesus Christ possessed a human will as well as a divine will, against the Monothelites, who asserted that in Jesus Christ there was only one single will.
Those are the five main stages in the Patristic doctrine of Christ, but to them we must add two more from modern times, which we shall consider in due course.
(vi) The Reformation, which sought to state the whole historic doctrine of Christ in East and West more in terms of Christ’s saving and reconciling mission, that is, in more dynamic terms.
(vii) Early Scottish theology (as in the teaching of Robert Boyd of Trochrig), and the theology of Karl Barth in our own day (after the assessment of the vast documentary study of the historical Jesus), where anhypostasia and enhypostasia are brought together to give full stress upon the historical Jesus Christ as the very Son of God. (Thomas F. Torrance, “Incarnation,” 196-97)