PETRA. - A city of Transjordan, characteristically built upon sheer cliffs, hence called *Sela* ("rock"), in Greek P. It was inhabited by the Edomites already in the early Iron Age, whose remains have come to light on the hill of Umm el-Bijārah; according to Jerome of Cardia (312), it was then without walls but naturally defended. It was occupied by the king of Judah Amaziah (797–779 BC), and the prisoners were cast down from the high cliffs (2 Chron. 25:12). It was reoccupied by the Edomites under the Syrian king Rezin. P. is mentioned in Isa. 42:11; Jer. 49:16 and in Obad. 3, which speaks of the lofty dwellings as eagles’ nests.
Occupied by the Nabataeans under Cyrus, it became the capital of the kingdom and acquired great importance. From that time began the building activity, with the construction of large and ornate rock-cut structures, which continued even under Roman rule (AD 106). In the desert city, divided in two by the Wādi Mūsā, there are still to be seen very many buildings: temples, a nymphaeum, a theatre, tombs, houses, etc., hewn from the rock by the natives, who attempted to imitate Greco-Roman motifs. The decorations are largely confined to architectural elements. At P. are also to be noted the high places of worship on el-Habis and el-Hubzeh. In the Christian period some buildings were converted into churches, e.g., the so-called Urn Tomb, which became a cathedral in 447 under Bishop Jason; others into hermitages, as at ed-Dejr. With the Arab occupation (7th century) the city became deserted and has remained so to this day; so much so that the Crusaders, who built a castle on el-Habis, seem not to have known its ancient name.