Cyclopedia of Biblical, Theological and Ecclesiastical Literature 
one of the earliest writers on Church History (between A.D. 150 and 180), was originally a Jew, born near the beginning of the 2nd century. He was converted to the Christian faith, and came to Rome about A.D. 168, where he died, according to the Alexandrine Chronicle, in the reign of Commodus, about A.D. 180. He wrote a collection of Υπομνήματα , or Memorials Of The History Of The Church, in five books, from the birth of our Lord to the time of Eleutherus, bishop of Rome, who succeeded Anicetus in A.D. 170. This work is all lost except a few fragments preserved by Eusebius, and one in the Bibliotheca of Photius. Several extracts may be found translated by Lardner (Credibility, vol. 2). All that remains of Hegesippus is given by Routh (Reliquiae Sacrae, 2nd edit. 1, 205 sq.), and also by Grabe (Spicilegium, 2, 203 sq.) and by Galland (Bibl. Patr. 2, 59). "The reports of Hegesippus on the character and martyrdom of St. James the Just, Simeon of Jerusalem, the rise of heresies, the episcopal succession, and the preservation of the orthodox doctrine in Corinth and Rome, as embodied in the history of Eusebius, command attention for their antiquity; but, as they show that his object was apologetic and polemical rather than historical, and as they bear a somewhat Judaizing (though by no means Ebionistic) coloring, they must be received with critical attention" (Schaff, Church History, vol. 1, § 123).
The Socinians of the 17th century use his brief statements as proof of' the general spread of Judaizing tendencies in the 1James, 2 nd centuries, and Baur, of T Ü bingen, and his school, have recently reproduced this view. Bishop Bull answered the former, and Dorner, in his Lehre v. d. Person Christi, 1, 219 (Edinburgh trans. 1, 139 sq.), has refuted the latter. "The evidence tends to prove that he was not even a Hebrew Christian in the sense of observing the law, and there is the most complete proof that he did not regard the observance of the law as essential to salvation. With the destruction of this premise, the keystone of the two theories of the early Unitarians and of Baur is utterly destroyed. The Unitarians maintained that Hegesippus was an Ebionite or Nazarene, and that consequently the whole Church was in his day Ebionitic? though, unfortunately, the few Platonizing writers, who formed a miserable exception to the mass, have been the only writers that a subsequent corrupt age has preserved to us. Baur finds in Hegesippus a most determined antagonist of Paul, and his testimony is appealed to as proof that the Petrine faction had gained the predominance not only in the churches of the East, but even in. those of the West. Both theories run directly contrary to the repeated testimony of Eusebius, and to all the information which we have in regard to the Western churches, and they both fall to pieces unless it be proved that Hegesippus insisted upon the observance of the law as essential to salvation" (Donaldson, History of Christian Literature, 3, 188 sq.). See also Clarke, Succession of Sacred Literature; Neander, Church History, 1, 675, 676; Lardner, Works, vol. 2; Cave, Hist. Lit. 1. 265; Fabricius, Bibl. Graeca, 7, 156; Dupin, Eccles. Writers, cent. 2; Illgen, Zeitschrift, 1865, pt. 3.
The Nuttall Encyclopedia 
A Church historian of the 2nd century, a convert from Judaism; only fragments of his "Memoirs of Ecclesiastical Affairs" remain.