A Modern Split Between Two Patriarchates Over Ukraine

The theoretical structure of patriarchs as equals in honour within a single communion was tested severely by a real jurisdictional rupture in 2018 and 2019, when the Ecumenical Patriarchate of Constantinople granted autocephaly, full independence, to a newly unified Orthodox Church of Ukraine, a decision the Patriarchate of Moscow rejected as an intrusion into what it considered its own canonical territory inherited from a seventeenth century transfer of jurisdiction; Moscow responded by breaking communion with Constantinople entirely, a rupture serious enough that clergy and sacraments recognised by one patriarchate are not straightforwardly recognised by the other.

Other autocephalous Orthodox churches have since had to decide, church by church, whether to recognise the new Ukrainian church, and their decisions have split roughly along lines of relationship with Moscow versus Constantinople rather than resolving into a single Orthodox-wide consensus, demonstrating in real time exactly the structural vulnerability of a communion built on formally equal patriarchs with no single higher authority empowered to settle a jurisdictional dispute between them once cooperation breaks down.