The minor seminary is in Sezze, and the major seminary in Anagni, shared with the other dioceses of lower Lazio. The episcopal residence is in Terracina.
I. TERACINA
It is the Volsci town of Anxur, which was situated on the slope of the hill overlooking the hinterland of the present city. After various vicissitudes it became the Roman Terracina, which prospered considerably thanks to its position on the sea and along the Via Appia. From the pontificate of Adrian I it belonged to the Papal States. In 1000 Sylvester II ceded it to Count Daiferio, and in 1071 Alexander II to the famous abbot Desiderius of Monte Cassino, until in 1150 Eugenius III redeemed II. The origins of Christianity in Terracina date back to the 1st century. The Greek apocryphal Acts of SS. Peter and Paul, composed in the 9th century, narrate the journey of the two Apostles from Baiae to Gaeta and from Gaeta to Terracina as they made their way to Rome. This fanciful tale may perhaps have led local historians to conclude that St. Paul preached in Terracina and that St. Peter founded the diocese. What remains more probable is that St. Paul spent a night in Terracina during his first journey to Rome.It is known that in the time of the emperor Domitian (81–96) Flavia Domitilla, wife of the consul Flavius Clemens, was exiled to the island of Ventotene (Dio Cassius, Hist. Rom., 67, 14), and Flavia Domitilla, the niece of the same, to Ponza (Eusebius, Hist. ecc., III, 18, 4). Both were Christians. The Acts of SS. Nereus and Achilleus (BHL, 6058–6067), from the second half of the 5th century, claim that the second Flavia Domitilla died and was buried in Terracina, and that two Roman virgins, her companions, Euphrosina and Theodora, were martyred and buried there under Trajan (98–117) by a holy deacon named Caesarius. The anonymous author of these Acts doubtless wished to honor the namesake martyr of Terracina, who appears in the *Martyrologium Hieronymianum* on 1 November and 21 April. The *Passio* (BHL, 1511–16), composed between the 5th and 6th centuries, states that he was martyred under Nero in Terracina and buried along the Via Appia, shortly before reaching the city from Rome. However, the Acts of SS. Nereus and Achilleus and the *Passio* of St. Caesarius are not probative regarding the time. What is certain is that a basilica was erected over the martyr’s tomb, belonging to the time of the persecutions, which also served as the original cathedral of Terracina, rebuilt in the 11th–13th centuries and remodeled in the 17th. On the hill of Terracina stood the famous monastery of St. Stephen on the Mountain, founded by St. Benedict himself, as is recorded in the *Dialogues* of St. Gregory the Great (II, 22). By the 17th century it was already in ruins.
At Paola, beneath the Circeo and in the Pontine Islands, which belonged to Terracina, Christian inscriptions have been discovered, one of which dates to 345 (CIL, X, 1, 6419–21; X, 11, 8412–13).
Analda, a local historian, opened the series of bishops of Terracina with Epaphroditus of the Epistle to the Philippians (II, 25), without adducing reasons. As P. Gams (Series episc., Ratisbon 1873, p. 731) includes the martyrs Quartus and Quintus, the first of whom, according to the *Passio* of St. Caesarius, would have been the buryer of the alleged martyr Eusebius. The first bishop of Terracina certainly known to us is Sabinus, in 313.
In the 11th century—though the exact date cannot be determined—Terracina was united with the dioceses of Priverno and Sezze, as is evident from the confirmation bull issued by Honorius III on 18 January 1217.
II. PRIVERNO
It corresponds to the Volsci town of Privatum, which was later colonized by the Romans and, destroyed in the Middle Ages, was rebuilt under the name Piperno, until in 1928 it resumed its ancient name. The diocese of Priverno first appears in a document of 769, but L. Duchesne believes it existed before the 7th century and was transferred to Sezze in 1039, unlike P. F. Kehr, who considers them two distinct dioceses. The reading of three martyrs’ names by G. B. De Rossi on a badly damaged inscription from Priverno has not been accepted.Within the diocese of Priverno lies the famous abbey of Fossanova, at the point where the Valle dell’Amaseno opens into the Pontine plain. Some have believed it to be the monastery of St. Stephen of Mileto, founded by St. Benedict and flourishing until the time of Innocent II, who in 1135 is said to have granted it to the Cistercians under the name of St. Pudentiana, later of St. Mary; P. F. Kehr believes it to be distinct and founded in 1027. The construction of the church, consecrated by Innocent III on 19 June 1208, constitutes the first example of Cistercian style, which developed in Burgundy as an evolution of the Lombard style. The fame of the abbey, however, is chiefly due to the death there of St. Thomas Aquinas. The church of St. Mary, formerly a cathedral and later collegiate, was restored as a cathedral with the same rights as that of Terracina by Benedict XIV on 10 September 1724.
III. S
It is the ancient Setia or Suessa of the Volsci. It rises on the top of a hill from which the view extends over the Agro Pontino and the Lepini Mountains. It was a Roman colony, and from the 8th century onward it was part of the Papal States. The diocese of S. appears for the first time in a document of 1036, but, as P. L. Duchesne believes, it may be anterior to the 7th century.In the 11th century, S. and P. were united with T. The church of S. Maria, a Roman construction rebuilt in 1347, was the cathedral, then a collegiate church, and again, on 29 April 1724, raised to the status of cathedral by Benedict XIV with the same rights as those of T. and P. In the diocese of S. flourished the monastery of S. Cecilia, founded by St Lindanus in the 11th century.
The dioceses of T., P., and S. have their court of appeal at the vicariate of Rome. – See plate CXLIII.