(c. 116–c. 125)
In the earliest succession lists Sixtus or (more correctly) Xystus was sixth bishop of Rome in the line inaugurated by the Apostles Peter and Paul. The later convention which reckoned St Peter the first pope counted him the seventh. Irenaeus lists twelve bishops of Rome between Peter and Eleutherius—bishop in Irenaeus' own day and known to him. This list explicitly links the twelve bishops to the twelve apostles: Sixtus is, rather suspiciously, the sixth. The dates of his reign are quite uncertain, but the early sources agree that it lasted about ten years. LP states that he was a Roman, the son of one Pastor; his name in its original form suggests Greek extraction. Nothing is known of his activities, the details supplied by LP about his supposed disciplinary and liturgical innovations being transparently anachronistic. Later tradition represented him as a martyr, and he is commemorated with the apostles and martyrs in the ancient canon of the mass; but the fact that Irenaeus, in his list, singles out only Telesphorus as having been one implies that Sixtus was not. LP's further report that he was buried near St Peter on the Vatican Hill has no foundation, and, as with other leaders of the Roman church in this period, no clear conception can be formed of his role in its government. Feast 3 Apr.
Irenaeus, Adv. haer. 3. 3. 3Eusebius, Hist. eccl. 4. 4. 1, 4. 5. 1, 5. 6. 4LP i, pp. ccviii, 54–7 (Davis 1: 4), 128Caspar i. 8–16DCB iv (J. Barmby)DTC xiv. 2193 f. (É. Amann)BSS xi. 1254–6 (M. da Alatri)NCE xiii. 194 (E. G. Weltin)Lampe