Gennadius of Massilia (died c. 496), also known as Gennadius Scholasticus or Gennadius Massiliensis, was a 5th-century Christian priest and historian.
His best-known work is De Viris Illustribus ("Of Famous Men"), a biography of over 90 contemporary significant Christians, which continued a work of the same name by Jerome.
Gennadius was a priest of Massilia (now Marseille) and a contemporary of Pope Gelasius I.
Nothing is known of his life, save what he tells us himself in the last of the biographies he wrote: "I, Gennadius, presbyter of Massilia, wrote eight books against all heresies, five books against Nestorius, ten books against Eutyches, three books against Pelagius, a treatise on the thousand years of the Apocalypse of John, this work, and a letter about my faith sent to blessed Gelasius, bishop of the city of Rome".
Gelasius reigned from 492-496, so Gennadius must have lived at the end of the 5th century.
Gennadius knew Greek well and was well read in Eastern and Western, orthodox and heretical Christian literature. He was a diligent compiler and a competent critic.
De Viris Illustribus, in its most commonly accepted form was probably published c. 495 and contains, in some ten folio pages, short biographies of ecclesiastics between the years 392 and 495. It is a very important source and in part the only source of our acquaintance with the over ninety authors treated therein.
It is a continuation of St. Jerome's De Viris Illustribus. In that work Jerome had for the first time drawn up a series of 135 short biographies of famous Christians, with lists of their chief writings. It was the first patrology and dictionary of Christian biography. This book of reference was so useful that it naturally became popular, and many people wrote continuations after the same method. We hear of such a continuation by one Paterius, a disciple of Jerome, and of a Greek translation by Sophronius.
It was Gennadius's continuation that became most popular and was accepted everywhere as a second part of Jerome's work, and was always written (eventually printed) together with his. Gennadius's part contains about one hundred lives, modelled closely after those of Jerome. Various edits and reprints do not number them consistently; by Bernoulli, i to xcvii, with some marked as xciib, etc., originally cxxxvi-ccxxxii).