Historically, Eastern Orthodoxy was an important denomination in the medieval and early modern Kingdom of Hungary.
[1] Between the middle of the 10th and the beginning of the 13th century, medieval Hungary had occasional political ties with the Byzantine Empire and Kievan Rus'.
In the middle of the 10th century, the Patriarchate of Constantinople sent a mission, headed by bishop Hierotheos, to the Principality of Hungary.
[4] In 1440, Hungarian king Ladislaus the Posthumous granted special privileges to Eastern Orthodox Christians for the establishment of the Serbian Kovin Monastery.
In 1481 and 1495, during the times of Turkish invasions, Hungarian kings Matthias Corvinus and Vladislaus II have granted special privileges to Eastern Orthodox Christians in order to secure demographic recovery and improve the defenses of southern frontiers.