Several Orthodox Churches
In 1054, after a long series of conflicts, Christendom fell apart into a Catholic (Latin) Church, governed from Rome, and an Eastern Orthodox Church, governed from Constantinople. This split is known as the Great Schism.
There is no single Orthodox church, but there are about fifteen different autonomous churches, often organized by country. Patriarch Kirill’s Russian Orthodox Church is the largest, with followers in Russia, Belarus and Ukraine. In the Netherlands there are Russian Orthodox churches in Rotterdam, The Hague and Amersfoort, among others.
Patriarch Bartholomew of Constantinople (present-day Istanbul) is the de facto leader of the Joint Orthodox Churches. However, his power is less than that of the Pope in the Roman Catholic Church. In 2018, Patriarch Bartholomew gave the newly founded Ukrainian Church autonomous status, much to the anger of the Russian Orthodox Church. Moscow then severed ties with Constantinople: a new schism.