Greek Christian historian and champion of orthodoxy who opposed the heresy of Gnosticism (q.v.). His single known work, five books of memoirs, constitutes a prime source on the organizational structure and theological ferment of the primitive Christian church.

Probably of Jewish descent, Hegesippus c. 180 composed his memoirs, containing a mélange of historical, doctrinal, polemical, and catechetical interpolations. In his memoirs he noted the succession of Roman bishops down to Pope Eleutherius (174–189), accenting, however, their doctrine rather than the chronology of succession. Recent scholarship infers Hegesippus' Hebraic background from the attention he pays in his memoirs to the Jewish-Christian community in Jerusalem and its history of episcopal leaders. The preservation of segments of his memoirs by the 4th-century historian Eusebius of Caesarea provides the most direct existing witness to the primitive church of Jerusalem and the fate of Palestinian Christianity as a result of the anti-Jewish pogrom conducted after AD 70 by the Roman emperors Vespasian and Domitian.