Cyriacus (correspondent of Nilus of Ancyra)

Cyriacus is known only as a recipient of letters from Nilus of Ancyra (d. c. 430), and would be active in the early-5th-century Ancyra (Galatia) milieu that Nilus's correspondence reflects. Nilus addresses him as a presbyter in most of the letters (and once as a deacon), and writes to him chiefly as a spiritual director: consoling him amid trials and demonic temptation, urging unceasing prayer and thanksgiving, expounding Scripture, and once warning him against literally cutting off the body's generative members, counseling instead an inward chastity through prayer. One letter also gives him doctrinal instruction on the eternal begetting of the Son from the Father, and another mentions his kinsman Pisimius as a virtuous man likewise afflicted by the devil. Beyond these eight letters Cyriacus is otherwise unattested.