The Photian schism

Jurisdictional · 863 — unsettled · east-west

A disputed succession at Constantinople became a quarrel about who may judge it, and then about the creed and the mission to Bulgaria.

How it ended. Photios was restored in 877 and the council of 879 undid the sentence of 869 — which is why the two churches count a different Fourth Council of Constantinople.

How it ran

863 — Photian Schism (where it began). The disputed succession at Constantinople.

What it broke

Schism, 863–867 communion was restored

The argument and the division are graded separately: this dispute is jurisdictional and what it broke is a schism.

The seats it ran between

Archbishop of Constantinople (Ecumenical Patriarch) a party to it
Bishop of Rome (Pope) a party to it

What was at issue

The Filioque what was at issue

Who stood in it

Photios I of Constantinople a principal

After The Orthodox Church in the Byzantine Empire · Hussey, part 1, on the Photian schism.