Demetrius did not long survive the execution of his vengeance against his unfortunate catechist. He died about a year afterwards, and was succeeded by Heraclas, the friend and former pupil of Origen. It does not, however, appear that Heraclas made any effort to have the sentence against Origen recalled, so that he might return to the early seat of his labours. Origen devoted himself at Cæsarea chiefly to exegetical studies upon the books of Scripture, enjoying the countenance and friendship of the two bishops Alexander and Theoctistus, who are said by Eusebius “to have attended him the whole time as pupils do their master.” He speedily raised the theological school of that city to a degree of reputation which attracted many pupils. Among those who placed themselves under his instructions were two young Cappadocians, who had come to Cæsarea with other intentions, but who were so attracted by the whole character and personality of Origen, that they immediately became his pupils. The former of these, afterwards Gregory Thaumaturgus, Bishop of New Cæsarea, has left us, in the panegyric which he wrote after a discipleship of five years, a full and admiring account of the method of his great master. The persecution under the Emperor Maximin obliged Origen to take refuge in Cæsarea in Cappadocia, where he remained in concealment about two years in the house of a Christian lady named Juliana, who was the heiress of Symmachus, the Ebionite translator of the Septuagint, and from whom he obtained several MSS. which had belonged to him. Here, also, he composed his _Exhortation to Martyrdom_, which was expressly written for the sake of his friends Ambrosius and Protoctetus, who had been imprisoned on account of their Christian profession, but who recovered their freedom after the death of Maximin,—an event which allowed Origen to return to the Palestinian Cæsarea and to the prosecution of his labours. A visit to Athens, where he seems to have remained some time, and to Bostra in Arabia, in order to bring back to the true faith Bishop Beryllus, who had expressed heterodox opinions upon the subject of the divinity of Christ, and in which attempt he proved successful, were the chief events of his life during the next five years. On the outbreak of the Decian persecution, however, in 249, he was imprisoned at Tyre, to which city he had gone from Cæsarea for some unknown reason, and was made to suffer great cruelties by his persecutors. The effect of these upon a frame worn out by ascetic labours may be easily conceived. Although he survived his imprisonment, his body was so weakened by his sufferings, that he died at Tyre in 254, in the seventieth year of his age.