Titular metropolitan see of Palæstina Tertia. Under the name of Sela (the rock) this region is described in Abdias (i, 3 sqq.) as an eagle's nest on the mountain top. It is also referred to in Isaias (xlii, 11), IV Kings (xiv, 7), and II Par. (xxv, 11). In the two last-mentioned passages it is related that towards the end of the ninth century B.C. Amasias, King of Jerusalem, vanquished the Edomites, captured Sela, and cast from "the steep of a rock" 10,000 captives, who were dashed to pieces. He then called Sela Ioqteel (Jectehel), of which there is no trace in history. If these Biblical texts really relate to Petra, others in which there is mention of Sela refer to other localities. Petra was not then the capital city of the Kingdom of Edom. This rank was held by Bosra, and Petra seems to have been a refuge whither in times of danger the chieftains fled with their treasures and dwelt in the caverns as in houses.
When the Rock was spoken of in 312 B.C. by Diodorus Siculus (XIX, 94-100), it was no longer inhabited by Edomites, who had been crowded into Southern Palestine, but by Arabian merchants, the Nabatæans or the Nabajoth of the Bible (Gen., XXV, 13; xxviii, 9; xxxvi, 3; Is., lx, 7). It is difficult to determine when they began to occupy the region. When conquered by Asurbanipal (640 B.C.), the Nabaitu were a powerful North-Arabian tribe which had fought its way as far as the countries of Edom, Moab, and Ammon. In the fourth century B.C. the Nabatæans were masters of the country and served as commercial intermediaries between Arabia and Egypt, and between Arabia and Syria. The wealth secured in Petra attracted the covetousness of Athenes, general of Antigonus (312 B.C). He took it by surprise in the absence of the men, who on their return surprised the Greeks, massacred them, and sent presents to Antigonus that they might be free to continue their commerce. A second attempt, made by Demetrius, son of Antigonus, was equally unsuccessful (Diod. Sic., XIX, 94-100). There was then formed a Nabatæan kingdom of which Petra was the capital and which extended from Arabia Felix to Hauran. The first known king was Aretas I (II Mach., v, 8). The following, according to M. Dusand in the "Journal Asiatique" (Paris, 1904, pp. 189-338), is the list of known sovereigns:
Aretas I (169 B.C.)
Aretas II (110-96)
Obodas I (about 90)
Rabel I (about 87)
Aretas III (87-62)
Obodas II (about 62-47)
Malichus I (about 47-30)
Aretas IV (9 B.C.-A.D. 40)
Malichus II (40-75)
Rabel II (75-101)
Malichus III (101-106)
Aretas III gave Petra its Græco-Roman character. From his reign and that of Aretas IV date most of the beautiful buildings still preserved. Petra was definitely annexed to the Roman Empire in A.D. 106 by Cornelius Palma, lieutenant of Trajan. From it was formed the Province of Arabia, "redacta in formam provinciæ Arabia", as Trajan's sign-posts read, extending from Bostra in Hauran to the Red Sea. In 295 the province was divided into Arabia Augusta Libanensis on the north, with Bostra as metropolis. Twelve years later Southern Arabia was united with the Province of Palestine to be again detached in the second half of the fourth century (between 358 and 390), and to constitute thenceforth Palæstina Tertia or Palæstina Salutaris, with Petra as metropolis. The custom arose of calling it Arabia Petræa, because of the city of Petra, and not with the implication that the region was rocky, for it is rather fertile. After a visit from the Emperor Hadrian Petra took the surname of Hadriana, found on the coins and on some inscriptions.
Christianity was introduced into Petra doubtless at an early date, for in the time of Strabo, who has described the country (XIV, iv, 21 sq.), Greek and Latin merchants flocked thither. Among its bishops Le Quien (Oriens christ., III, 721-8), mentions St. Asterius, whose feast is celebrated on 20 June, one of the defenders of the Council of Nicæa and St. Athanasius; his contemporary Germanus, probably an Arian; John (457); Theodore (536), biographer of St. Theodosius the Cenobite; Athenogenes, a relative of the Emperor Maurice (end of the sixth century). An inscription indicates likewise a bishop by the name of Jason (probably fifth century). The Diocese of Petra in Palestine, mentioned by Le Quien (ibid., III, 663-70), who relied on a faulty text of St. Athanasius, never existed. In the time of John Moschus (seventh century) Petra was a flourishing monastic centre, but the decline of the city was even then far advanced, because the direction of commerce had changed and the prosperity of Palmyra had injured that of Petra. When the Franks took possession of the country in the twelfth century and founded their Trans-Jordanic principality they established somewhat prior to 1116 a stronghold called "Li Vaux Moyse", a translation of the Arabic name Ouadi-Moussa, the ruins of which have been discovered near the village of El-Dji. It was captured by the Arabs, first in 1144 and definitively in 1188. The Latin archdiocese, called Petra Deserti, which was established by the crusaders in 1168, must not be confused with our Petra; the former is Charac-Moba, the ancient capital of the Moabites, now El-kerac (Le Quien, ibid., III, 1305); Du Cange, Les familles d'Outre-mer, Paris, 1859, p. 755; Eubel, Hierarchia catholica medii ævi, I, 418).
Petra, now Ouadi-Moussa, is completely ruined. Of the Græco-Roman city there remain, besides the theatre hewn from the rock, only shapeless ruins; but the tombs dug in the sides of the mountain surrounding the city are one of the wonders of the world. There are more than 3000, of different periods. Archæology, it is true, regards some of them as temples. As the red sandstone from which the tombs are hewn is veined with a variety of colours, and as the light is dazzling, this city of the dead presents the appearance of a veritable fairy-land, the like of which is not to be seen elsewhere in the world. Recently the high place and the site of the altar of sacrifice have been discovered.
When the late Archbishop of New York, Michael Augustine Corrigan, was coadjutor to Cardinal McCloskey, his titular see was that of Petra.
Laborde, Voyage dans l'Arabie Pétrée (Paris, 1830-34); Wilson, The Lands of the Bible, I (Edinburgh), 291-336; Stanley, Sinai and Palestine (London, 1860), 87-98; Palmer, The Desert of Exodus, II (London, 1871); Libbey, The Jordan Valley and Petra (New York, 1905); Luynes, Voyage d'exploration à la Mer Morte etc. (Paris, 1871); 274; Buhl, Gesch. der Edomiter (Leipzig, 1893); Brunnow and Domaszewski, Die Provinicia Arabia, I (Strasburg, 1904); Musil, Arabia Petræa, II (Vienne, 1907); Dalman, Petra und seine Felsheiligstümer (Leipzig, 1908); Sargenton-Galichon, Sinai, Maân, Pétra (Paris, 1904); Revue Biblique (1897; 1898; 1902; 1903); Kergorlay, Sites délaissés d'Orient (Paris, 1911), 91-154.
Siméon Vailhé, Catholic Encyclopedia, Volume 11. (1913)