Dionysius (7) , bp. of Rome; a Greek by birth, consecrated July 22, a.d. 259, on the death of Xystus, in the persecution of Valerian. His efforts against heresy are recorded. When Dionysius of Alexandria (q.v. ) was accused of holding doctrines akin to those of Sabellius, the Roman Dionysius wrote to him, and extracted so satisfactory a defence that he declared him purged of suspicion (Athan. Ep. de Sent. Dionys. Opp. i. 252; see an Eng. trans. of the Fragm. against Sabellius in Ante-Nicene Lib. ). In 264 the Alexandrian and Roman Dionysii acted together with the council of Antioch in condemning and degrading Paul of Samosata. Dionysius of Rome died Dec. 26, 269.