Born about 334; died 26 November, 399, Siricius was a native of Rome; his father's name was Tiburtius. Siricius entered the service of the Church at an early age and, according to the testimony of the inscription on his grave, was lector and then deacon of the Roman Church during the pontificate of Liberius (352-66). After the death of Damasus, Siricius was unanimously elected his successor (December, 384) and consecrated bishop probably on 17 December. Ursinus, who had been a rival to Damasus (366), was alive and still maintained his claims. However, the Emperor Valentinian III, in a letter to Pinian (23 Feb., 385), gave his consent to the election that had been held and praised the piety of the newly-elected bishop; consequently no difficulties arose. Immediately upon his elevation Siricius had occasion to assert his primacy over the universal Church. A letter, in which questions were asked on fifteen different points concerning baptism, penance, church discipline, and the celibacy of the clergy, came to Rome addressed to Pope Damasus by Bishop Himerius of Tarragona, Spain. Siricius answered this letter on 10 February, 385, and gave the decisions as to the matters in question, exercising with full consciousness his supreme power of authority in the Church (Coustant, "Epist. Rom. Pont.", 625 sq.). This letter of Siricius is of special importance because it is the oldest completely preserved papal decretal (edict for the authoritative decision of questions of discipline and canon law). It is, however, certain that before this earlier popes had also issued such decretals, for Siricius himself in his letter mentions "general decrees" of Liberius that the latter had sent to the provinces; but these earlier ones have not been preserved. At the same time the pope directed Himerius to make known his decrees to the neighbouring provinces, so that they should also be observed there. This pope had very much at heart the maintenance of Church discipline and the observance of canons by the clergy and laity. A Roman synod of 6 January, 386, at which eighty bishops were present, reaffirmed in nine canons the laws of the Church on various points of discipline (consecration of bishops, celibacy, etc.). The decisions of the council were communicated by the pope to the bishops of North Africa and probably in the same manner to others who had not attended the synod, with the command to act in accordance with them. Another letter which was sent to various churches dealt with the election of worthy bishops and priests. A synodal letter to the Gallican bishops, ascribed by Coustant and others to Siricius, is assigned to Pope Innocent I by other historians (P.L., XIII, 1179 sq.). In all his decrees the pope speaks with the consciousness of his supreme ecclesiastical authority and of his pastoral care over all the churches.
Siricius was also obliged to take a stand against heretical movements. A Roman monk Jovinian came forward as an opponent of fasts, good works, and the higher merit of celibate life. He found some adherents among the monks and nuns of Rome. About 390-392 the pope held a synod at Rome, at which Jovinian and eight of his followers were condemned and excluded from communion with the Church. The decision was sent to St. Ambrose, the great Bishop of Milan and a friend of Siricius. Ambrose now held a synod of the bishops of upper Italy which, as the letter says, in agreement with his decision also condemned the heretics. Other heretics including Bishop Bonosus of Sardica (390), who was also accused of errors in the dogma of the Trinity, maintained the false doctrine that Mary was not always a virgin. Siricius and Ambrose opposed Bonosus and his adherents and refuted their false views. The pope then left further proceedings against Bonosus to the Bishop of Thessalonica and the other Illyrian bishops. Like his predecessor Damasus, Siricius also took part in the Priscillian controversy; he sharply condemned the episcopal accusers of Priscillian, who had brought the matter before the secular court and had prevailed upon the usurper Maximus to condemn to death and execute Priscillian and some of his followers. Maximus sought to justify his action by sending to the pope the proceedings in the case. Siricius, however, excommunicated Bishop Felix of Trier who supported Ithacius, the accuser of Priscillian, and in whose city the execution had taken place. The pope addressed a letter to the Spanish bishops in which he stated the conditions under which the converted Priscillians were to be restored to communion with the Church.
According to the life in the "Liber Pontificalis" (ed. Duchesne, I, 216), Siricius also took severe measures against the Manichæans at Rome. However, as Duchesne remarks (loc. cit., notes) it cannot be assumed from the writings of the converted Augustine, who was a Manichæan when he went to Rome (383), that Siricius took any particular steps against them, yet Augustine would certainly have commented on this if such had been the case. The mention in the "Liber Pontificalis" belongs properly to the life of Pope Leo I. Neither is it probable, as Langen thinks (Gesch. der röm. Kirche, I, 633), that Priscillians are to be understood by this mention of Manichæans, although probably Priscillians were at times called Manichæans in the writings of that age. The western emperors, including Honorius and Valentinian III, issued laws against the Manichæans, whom they declared to be political offenders, and took severe action against the members of this sect (Codex Theodosian, XVI, V, various laws). In the East Siricius interposed to settle the Meletian schism at Antioch; this schism had continued notwithstanding the death in 381 of Meletius at the Council of Constantinople. The followers of Meletius elected Flavian as his successor, while the adherents of Bishop Paulinus, after the death of this bishop (388), elected Evagrius. Evagrius died in 392 and through Flavian's management no successor was elected. By the mediation of St. John Chrysostom and Theophilus of Alexandria an embassy, led by Bishop Acacius of Beroea, was sent to Rome to persuade Siricius to recognize Flavian and to readmit him to communion with the Church.
At Rome the name of Siricius is particularly connected with the basilica over the grave of St. Paul on the Via Ostiensis which was rebuilt by the emperor as a basilica of five aisles during the pontificate of Siricius and was dedicated by the pope in 390. The name of Siricius is still to be found on one of the pillars that was not destroyed in the fire of 1823, and which now stands in the vestibule of the side entrance to the transept. Two of his contemporaries describe the character of Siricius disparagingly. Paulinus of Nola, who on his visit to Rome in 395 was treated in a guarded manner by the pope, speaks of the urbici papæ superba discretio, the haughty policy of the Roman bishop (Epist., V, 14). This action of the pope is, however, explained by the fact that there had been irregularities in the election and consecration of Paulinus (Buse, "Paulin von Nola", I, 193). Jerome, for his part, speaks of the "lack of judgment" of Siricius (Epist., cxxvii, 9) on account of the latter's treatment of Rufinus of Aquileia, to whom the pope had given a letter when Rufinus left Rome in 398, which showed that he was in communion with the Church. The reason, however, does not justify the judgment which Jerome expressed against the pope; moreover, Jerome in his polemical writings often exceeds the limits of propriety. All that is known of the labours of Siricius refutes the criticism of the caustic hermit of Bethlehem. The "Liber Pontificalis" gives an incorrect date for his death; he was buried in the cæmeterium of Priscilla on the Via Salaria. The text of the inscription on his grave is known (De Rossi, "Inscriptiones christ. urbis Romæ", II, 102, 138). His feast is celebrated on 26 November. His name was inserted in the Roman Martyrology by Benedict XIV.
(Taken from Catholic Encyclopedia)