While the Eastern Orthodox Church gives a certain honor to the Roman Catholic pope, they don’t see him as having ultimate authority over the Church. However, there was a time in early Church history when many of the Eastern Orthodox’s spiritual forbearers did accept papal primacy: through the 6th-century Formula of Pope St. Hormisdas.
After the Council of Chalcedon concluded in 451, a schism arose in the Eastern Church. Some bishops — including those from Constantinople — strayed from the council’s teachings.
For them to be reconciled to the Catholic Church, they had to sign Pope Hormisdas’ formula, wherein he taught papal supremacy. Many Eastern bishops of the 6th century did so, signaling their agreement. (Modern Eastern Orthodox members reject this belief.)
The formula states:
“The first condition of salvation is to keep the norm of the true faith and in no way to deviate from the established doctrine of the Fathers.