The History of Orthodox Christianity: Origins and Early Development (Part 1/3) ✝️

The history of the Eastern Orthodox Church is traced back to Jesus Christ and the Apostles. The Apostles appointed successors, known as bishops, and they in turn appointed other bishops in a process known as Apostolic succession. Over time, five Patriarchates were established to organize the Christian world, and four of these ancient Patriarchates remain Orthodox today. Orthodox Christianity reached its present form in Late Antiquity (in the period from the 3rd to the 8th century), when the Ecumenical Councils were held, doctrinal disputes were resolved, the Fathers of the Church lived and wrote, and Orthodox worship practices settled into their permanent form (including the liturgies and the major holidays of the Church).

In the early medieval period, Orthodox missionaries spread Christianity towards the north, to the Bulgarians, Serbs, Russians and others. Meanwhile, a gradual process of estrangement took place between the four Eastern Patriarchates and the Latin Church of Rome, culminating with the Great Schism in the 11th century, in which Orthodoxy and the Latin Church (later called the Roman Catholic Church) separated from each other. In the Late Middle Ages, the Fall of Constantinople brought a large part of the world's Orthodox Christians under Ottoman Turkish rule. Nevertheless, Orthodoxy continued to flourish in Russia, as well as within the Ottoman Empire among the latter's Christian subject peoples. As the Ottoman Empire declined in the 19th century and several majority-Orthodox nations regained their independence, they organized a number of new autocephalous Orthodox churches in Southern and Eastern Europe.

The Eastern Orthodox jurisdictions with the largest number of adherents in modern times are the Russian and the Romanian Orthodox churches. The most ancient of the Eastern Orthodox communities existing today are the churches of Jerusalem, Antioch, Alexandria, Constantinople, and Georgia.