Sent to Anastasius, Bishop of the City of Rome.
This document was called forth by accusations against Rufinus made, soon after his accession, to Anastasius, who held the Roman see from 498 to 503. The authority of the Roman Popes at this time was not what it afterwards became, and it is improbable that Anastasius should have summoned Rufinus, as some suppose him to have done, from Aquileia, where he was living on confidential terms with the Bishop Chromatius, to come to Rome to answer a formal accusation or to be judged by him. But since Rome was the centre of information, a Christian would not wish to be ill-thought of by its Bishop. Those who accused Rufinus were the friends of Jerome at Rome, especially the noble widow Marcella and the Senator Pammachius. They had endeavoured to gain some condemnation of Rufinus from Siricius before his death in November 398; but Siricius befriended Rufinus (“his simplicity was imposed on,” according to Jerome). On the election of Anastasius, however, in 399, they accused Rufinus of having, by his translation of Origen's Περὶ ᾿Αρχῶν introduced heresy into the Roman church. Jerome thus speaks of Marcella, Epistle 127:10. “She was the cause of the condemnation of the heretics: she brought witnesses who had been at a former time under their instruction, and thus imbued with error and heresy; she showed how many there were who had been deceived; she had the volumes of the Περὶ ᾿Αρχῶν brought in, and pointed out the alterations which the Scorpion had made in them: till at last letters were written, and that more than once, summoning the heretics to come and defend themselves, but they did not dare to come. So great was the force of conviction brought to bear on them that, to prevent their heresy being exposed in their presence, they chose to stay away and be condemned.” From the letter of Anastasius to John of Jerusalem about Rufinus we gather that, while he strongly disapproved the translation of Origen, he left Rufinus himself to his own conscience, and did not care to know what had become of him. The letter of Rufinus, though called an Apology, bears no trace of being an answer to a summons or judgment of the Pontiff, but merely a reply to statements which were likely to prejudice him in the Pontiff's opinion. The year in which the Apology was written was 400 a.d.
Source: Apology (New Advent)