Biblioth., VIII, 23) says: "de Eusebio qui vulgo dicitur episcopus Alexandræ incerta omnia" (Concerning Eusebius, commonly called bishop of Alexandria there is nothing sure).
According to an old biography said to have been written by his notary, the monk John, and discovered by Cardinal Mai, he lived in the fifth century and led a monastic life near Alexandria.
After having ruled his see for seven or, according to another account, for twenty years, he made Alexander his successor and retired to the desert, whence Cyril had summoned him and there died in the odor of sanctity.
It may be noted, however, that the biographer of Eusebius expressly states that the Cyril in question is the great opponent of Nestorius.
Mai suggests that after the death of Cyril, there were two bishops at Alexandria, Dioscurus, the Monophysite leader, and Eusebius, the head of the Catholic party.
The homilies cover a variety of subjects, and the author is one of the earliest patristic witnesses to the doctrine regarding the descent of Christ into Hell.