Semi-Autonomous: Eusebius says that Hegesippus was a convert from Judaism, learned in the Semitic languages and conversant with the oral tradition and customs of the Jews, for he quoted from the Hebrew, was acquainted with the Gospel of the Hebrews[5] and with a Syriac Gospel, and he also cited unwritten traditions of the Jews.

Eusebius' own shaky command of Hebrew and Aramaic,[6] and his lack of personal knowledge of customs of the Jews, were insufficiently founded to judge Hegesippus as a dependable source.

[7] He seems to have lived in some part of the East, for, in the time of Pope Anicetus (A.D. 155–166) he travelled through Corinth to reach Rome, collecting on the spot the teachings of the various churches which he visited, and ascertaining their uniformity with Rome, according to this excerpt: Hegesippus' works are now entirely lost, save eight passages concerning Church history quoted by Eusebius,[9] who tells us that he wrote Hypomnemata (Ὑπομνήματα; "Memoirs" or "Memoranda"[10]) in five books, in the simplest style concerning the tradition of the Apostolic preaching.

[16] He also transcribes from Hegesippus the story of the election of his successor Simeon, and the summoning of the descendants of Jude the Apostle to Rome by the Emperor Domitian.

It is very likely that the dating of heretics according to papal reigns in Irenaeus and Epiphanius—e.g., that Marcion's disciple Cerdon and Valentinus came to Rome under Anicetus—was derived from Hegesippus, and the same may be true of the assertion that Hermas, author of The Shepherd of Hermas, was the brother of Pope Pius I (as the Liberian Catalogue, the poem against Marcion, and the Muratorian fragment all state).