 After returning to Istanbul in 1968, he took a position at the Patriarchal Theological Seminary of Halki, where he was ordained a priest in 1969, by Ecumenical Patriarch Athenagoras I.When Demetrius I became ecumenical patriarch in 1972 and established the Patriarchal Office, he selected Bartholomew as its director.On Christmas of 1973, Bartholomew became metropolitan of Philadelphia, and was renamed as director of the patriarchal office until his enthronement as Metropolitan of Chalcedon in 1990.