118–126. They were discussed in Büdinger, Untersuch. zur röm. Kaisergesch, ii. 262, iii. 321–338, with elaborate archaeological and chronological commentaries.
[G.T.S.]
Sisinnius (7), a bishop of the Novatianists at Constantinople, succeeding on Marcian's death in Nov. 395 (Socr. H. E. v. 21; vi. 1; Soz. H. E. viii. 1). He published a treatise warmly controverting Chrysostom's impassioned language as to the efficacy of repentance and the restoration of penitents to communion, de Poenitentia (Socr. H. E. vi. 21). Chrysostom, taking umbrage at this and at his claim to exercise episcopal functions in Constantinople, threatened to stop his preaching. Sisinnius jocosely told him he would be much obliged to him for sparing him so much trouble, and thus disarmed his anger (ib. 22). Sisinnius enjoyed a great reputation for witty repartees. Several are collected by Socrates (l.c.), but do not give a very high idea of his powers. He is described as a man of great eloquence, enhanced by dignity of countenance and person, gracefulness of action, and by the tones of his voice. He had a considerable reputation for learning, being very familiar with philosophical writings as well as expositions of Scripture, and was well skilled in dialectics. Together with Theodotus of Antioch he composed a synodic letter against the Thessalians, in the name of the Novatianist bishops assembled at Constantinople for his consecration, addressed to Berinianus, Amphilochius, and other bishops of Pamphylia (Phot. Cod. Iii. col. 40; Cave, Hist. Lit. i. 290). Though a bishop of a schismatic body, he was much esteemed by the orthodox bishops, especially by Atticus, and was the honoured friend of leading aristocrats of Constantinople. He kept a sumptuous table, though not exceeding the bounds of moderation himself. Sisinnius died the same year as Chrysostom, a.d. 407, and was succeeded by Chrysanthus (Socr. H. E. vii. 6; Cave, u.s.).
[E.V.]
Sixtus I.—so called in the Liberian Catalogue by Optatus (l. 2) and Augustine (Ep. liii.); but Xystus, Xistus, or Xestus, in Catal. Felic., Irenaeus (adv. Haer. iii. 3), Eusebius (H. E. iv. 4, 5, and Chron.), Epiphanius (Haer. 97, 6)—one of the early bps. of Rome, called the 6th after the apostles, and the successor of Alexander. All assign him an episcopate of about 10 years, and place him in the reign of Hadrian. Catal. Liber. dates his episcopate 117–126; Eusebius (H. E.) 119–128; his Chronicle 114–124. Lipsius (Chronol. der röm. Bischöf.) gives 124–126 as the possible limits for his death. The Felician Catalogue and the Martyrologies represent him as a martyr, and he is commemorated among the apostles and martyrs, after Linus, Cletus, Clemens, in the canon of the mass. But Telesphorus being the first bp. of Rome designated a martyr by Irenaeus, the claim to the title of Sixtus and other early bps. of Rome, to the great majority of whom it has been since assigned, is doubtful.
[J.B—Y.]
Sixtus II. (Xystus), bp. of Rome after Stephen for about one year, martyred under Valerian Aug. 6, 258. A contemporary letter of St. Cyprian (Ep. 80) confirms this date as given in the Liberian Catalogue. Probably his accession was on Aug- 31, 257 (see Lipsius, Chronol. der röm. Bischöf.). His predecessor Stephen had been at issue with Cyprian of Carthage as to the rebaptism of heretics. Under Xystus, who was more conciliatory, though he upheld the Roman usage, peace was restored (Eus. H. E. vii. 5–7).
The circumstances of his martyrdom appear to have been as follows. The emperor Valerian had already, before the accession of Xystus, forbidden the resort of Christians to the cemeteries on pain of banishment. But in the middle of 258, when Valerian was arming for his Persian war, he sent a rescript to the senate of much severer import; ordering bishops, priests, and deacons to be summarily executed; senators and other persons of rank to be visited with loss of dignity and goods, and, on refusal to renounce Christianity, with death; matrons to be despoiled and exiled; and imperial officials (Caesarians) to be sent in chains to labour on the imperial domains (Cyp. Ep. 80). Xystus fell an early victim to this rescript. He was found by the soldiers seated on his episcopal chair, in the cemetery of Praetextatus on the Appian Way, surrounded by members of his flock. As these endeavoured to protect him, he thrust himself forward lest they should suffer in his stead, and was beheaded and several companions slain. His body was afterwards removed by the Christians to the usual burial place of the bishops of that period, the neighbouring cemetery of Callistus. His two deacons, Agapetus and Felicissimus, with others, were buried in the cemetery where they fell. This account of the occurrence is gathered from Cyprian's contemporary letter to Successus (Ep. 80), and from the Damasine inscription in the papal crypt of the cemetery of Callistus, of which a few fragments have been found by De Rossi, and which originally began as follows:
"Tempore quo gladius secuit pia viscera matris
Hic positus rector coelestia done docebam . . ."
(Gruter, 1173, 13)
That these verses refer to Xystus, and not, as assumed in the Acts of St. Stephen, to his predecessor, is satisfactorily shewn by Lipsius (op. cit.). That he was buried there is expressly stated in the Liberian Catalogue of Martyrs, as well as by all later authorities; and the statement is confirmed by numerous graffiti on the walls of the crypt, in which his name is prominent. The line "Hic positus," etc., may refer to the cathedra on which he sat when found by the soldiers, which had been removed with his body to the papal crypt. That the cemetery of Praetextatus was the scene of his martyrdom ancient tradition bears witness, and in accordance with it an oratory was afterwards built on the spot, "coemeterium ubi decollatus est Xystus." The tradition is confirmed by representations of him and his chair in this cemetery, under one of which is the legend SVSTVS.
[J.B—Y.]
Sixtus III., bp. of Rome (432–441) after Coelestinus, and the immediate predecessor of Leo the Great. Two notable heresies of his day were Pelagianism and Nestorianism. Before his accession he had taken part in both controversies. It appears from Augustine's letters
