ACATHIUS (ACACIUS) (St.) Bp. (April 9) (5th cent.) A Bishop of Amida in Mesopotamia, distinguished for his compassionate charity to the Persian prisoners taken in their successful invasion of Persia by the Romans of Constantinople in the reign of King Bahram (or Varannes) V, who is said chiefly on that account to have ceased for a time from persecuting the Christians. St. Acathius died some time after A.D. 421. Some of his letters are still extant.