Eustathius

Eustathius is known only as a correspondent of Isidore of Pelusium, who addresses him across these eight letters as both deacon and presbyter, placing him among the clergy in Isidore's early-to-mid-5th-century Pelusium milieu in the eastern Nile Delta. Isidore writes to him almost entirely in a corrective vein: urging him to bear with philosophic forbearance the insults of the presbyter Zosimus, rebuking his ill-will toward the bishop Eusebius, twice admonishing him against gluttony, and counseling him to write enmity in water and friendship in bronze rather than nurse a grudge. The gravest letter charges him with a dreadful deed of impiety and "false belief" (kakodoxia, erroneous or heretical doctrine), which Isidore implores him to cast off. He is otherwise unattested, surviving as a junior cleric repeatedly disciplined by Isidore on matters of conduct and orthodoxy.