1. Concept. Councils or Synods are assemblies (σύνοδοι, concilia) of representatives of the universal Church or local Churches for mutual consultations and for reaching decisions on Church affairs. A distinction must be drawn between Ecumenical Councils representing the universal Church and the various kinds of particular councils (general, patriarchal, plenary, primatial, imperial and provincial synods).

2. Historical sketch. The forms taken even by the Ecumenical Councils have been of diverse kinds. According to exis…