High priest (Hebrew, kohen gadol) is the chief priest of the Jerusalem Temple. According to Leviticus 21, the high priest was the descendent of Aaron who had been anointed with holy oil as the “chief priest” (Exodus 28:1). By the Hellenistic period the chief priest was responsible for the religious life of the country, and was the recognized representative of the Jewish community. Thus even when the Hasmoneans ruled as kings, they recognized that they would also have to hold the high priesthood if they were to exercise any real authority (a usurpation which caused the first schisms, leading to the community at Qumran). At the end of the second Temple period, when the territory was ruled by the Romans, the high priest was frequently considered merely the arm of the secular administration and came under constant criticism from the Pharisees and Zealots. In 70 AD, with the destruction of the Temple, the office lapsed. A.G.H.
Bowker, John, The Oxford Dictionary of World Religions, New York, Oxford University Press, 1997, p. 428