Between the 4th and 8th centuries, the Church held seven Ecumenical Councils. These gatherings were crucial because they formulated Christian dogma and combated heresies like Arianism and Iconoclasm.
was established during this time, defining the nature of the Holy Trinity.
Thesis statement: The Orthodox Church maintained early Christian traditions while adapting to geopolitical shifts, resulting in a unique synthesis of theology, culture, and national identity. Istoria Biserici Ortodoxe
The Orthodox Church views itself as the direct, uninterrupted continuation of the original Christian community established by Jesus Christ and His Apostles. In its early centuries, the Church was organized around five major patriarchal sees (the Pentarchy): Rome, Constantinople, Alexandria, Antioch, and Jerusalem. The Era of the Seven Councils
Istoria Bisericii Ortodoxe Române by Mircea Păcurariu — The definitive source if you are focusing specifically on the Romanian Orthodox Church context. Between the 4th and 8th centuries, the Church
Tensions gradually mounted between the Greek-speaking East and the Latin-speaking West. Disagreements over papal supremacy and the Filioque clause (the insertion of "and the Son" into the Creed by the Western Church) led to the Great Schism in 1054. This event formally divided the Chalcedonian Church into the Roman Catholic Church and the Eastern Orthodox Church. Captivity and Expansion
The Ecumenical Patriarch was granted religious and administrative authority over all Orthodox Christians in the empire, preserving the faith under Islamic rule. The Era of the Seven Councils Istoria Bisericii
Moscow as the "Third Rome" and the expansion of the Russian Church.