the seven ecumenical councils

The Fourth Ecumenical Council, Chalcedon
Chalcedon, 451: the definition of Christ as one person in two natures, with the council's canons.
The Third Ecumenical Council, Ephesus
Ephesus, 431: the council on the unity of Christ's person and the title Theotokos.

The Seven Ecumenical Councils

The canons, definitions, and records of the councils that framed the church's confession of Christ.