Tradition
Gennadius of Marseilles
Illustrious Men (Supplement to Jerome)
Chapter 90
Gennadius a Patriarch of the church of Constantinople, a man brilliant in speech and of strong genius, was so richly equipped by his reading of the ancients that he was able to expound the prophet Daniel entire commenting on every word.
He composed also many Homilies. He died while the elder Leo was Emperor.
Source: Illustrious Men (Supplement to Jerome) (New Advent)