Contents is a work document, containing correct but not complete information. The term "High priest" applies to more religions than the ones listed here.
Ancient Egyptian religion
Among the many priests of Ancient Egypt only the high priest was allowed to come in physical contact with the divine representations.
High priests had great influence over religion and society. In some eras, the high-priest was influential enough to topple the political power. This was especially the case with the High Priest of Amon at Thebes during the New Kingdom.