Primus inter pares
Primus inter pares, or first among equals, is a Latin phrase indicating that a person is the most senior of a group of people sharing the same rank or office. Usually, the role is considered a necessary inclusion in a system in which all parties are equal.
In the Orthodox Church, the Ecumenical Patriarch of Constantinople (currently His All-Holiness Bartholomew I) fulfils this role. Historically, the bishop of Rome was considered the first among equals of the pentarchy. The rising amount of power claimed by the pope, along with other factors, was the ecclesiological reason for the Great Schism. After the Schism, however, the role of first among equals fell to the patriarch of Constantinople.
On Mount Athos, the head of civil administration, styled protos (first), is elected for a limited time to govern the civil aspects of the Holy Mountain.
Some political examples include the Prime Minister of many Commonwealth nations, the President of the European Commission, and the Chief Justice of the United States Supreme Court. The term was also used by Roman Emperors as a means of reducing the appearance of dictatorship, particularly important during the early Roman Empire to appease those who may have longed for a return to the old Roman Republic.
This also applies to religious figures outside of the Orthodox Church. The Dean of the College of Cardinals is considered to be the primus inter pares of this College in the Roman Catholic Church. In the Anglican Communion, the Archbishop of Canterbury is often considered to be "first among equals". The Moderator of the General Assembly in a Presbyterian church is similarly designated. The senior bishop of the seven diocesean bishops of the Scottish Episcopal Church bears the truncated title Primus from primus inter pares.
The phrase "first among equals" is also used by some to describe the role of the Patriarch of Constantinople, who, as the Ecumenical Patriarch, is considered the first among all the Patriarchs of the Eastern Orthodox Churches. According to those views, the title does not mean that the holder has special authority over the other bishops; rather, it is an acknowledgement of his historic significance.
This is not the view of the Roman Catholic Church, which considers the pope to be Vicar of Christ, successor of Saint Peter, and absolute leader of the bishops, successors of the Apostles. Because of this, the Roman Catholic Church sees the pope as holding an office senior to that of other bishops, rather than merely being the most senior bishop. This claim was one of the main causes of the Great Schism between the Roman Catholic Church and the Orthodox Church around 1054.