Primus inter pares (Greek: Πρῶτος μεταξὺ ἴσων (protos metaxy ison), English: the first among equals or first among peers) is a Latin phrase describing the most senior person of a group sharing the same rank or office.
When not used in reference to a specific title, it may indicate that the person so described is formally equal, but looked upon as an authority of special importance by their peers. However, in some cases it may also be used to indicate that while the person described appears to be an equal, they actually are the group's unofficial or hidden leader, and thus the reference to this person being "equal" to the rest is intended to project mutual respect and camaraderie.
The term is used with reference to the Roman Emperors' way of reducing the appearance of dictatorship (which was particularly important during the early Roman Empire to appease those who may have longed for a return to the old Roman Republic; see Princeps). Other examples include the Prime Minister of many parliamentary regimes, the President of the European Commission, the Chief Justice of the United States, and some religious figures, such as the Dean of the College of Cardinals of the Roman Catholic Church, or the Ecumenical Patriarch of the Eastern Orthodox Church.