ancient city in south-central Syria, 130 miles (210 km) northeast of Damascus. The name Palmyra, meaning “city of palm trees,” was conferred upon the city by its Roman (ancient Rome) rulers in the 1st century CE; Tadmur, Tadmor, or Tudmur, the pre-Semitic name of the site, is also still in use. The city is mentioned in tablets dating from as early as the 19th century BCE. It attained prominence in the 3rd century BCE, when a road through it became one of the main routes of east-west trade. Palmyra was built on an oasis lying approximately halfway between the Mediterranean Sea (west) and the Euphrates River (Tigris-Euphrates river system) (east), and it helped connect the Roman world with Mesopotamia (Mesopotamia, history of) and the East.

The city thus prospered, and the 2nd and 3rd centuries CE were the great age of Palmyra and its extensive trading activities, despite obstacles that interrupted caravan trade with the East, and also in the face of instability around the Roman-controlled Mediterranean. When the Sāsānians (Sāsānian dynasty) supplanted the Parthians (Parthia) in Persia and southern Mesopotamia (227), the road to the Persian Gulf was soon closed to Palmyrene trade. These difficulties led the Romans to set up the personal rule of the family of Septimius Odaenathus (Odaenathus, Septimius) at Palmyra. He was appointed governor of Syria Phoenice by the emperor Valerian (reigned 253–260), but it was apparently his son, the emperor Gallienus, who conferred on Odaenathus the title of corrector totius Orientis (“governor of all the East”). Both Odaenathus and his eldest son, the heir apparent, were assassinated, however, reputedly at the command of Odaenathus' second wife, Zenobia, who took control of the city and became an effective leader. Under her rule, the armies of Palmyra conquered most of Anatolia (Asia Minor) in 270, and the city declared its independence from Rome. The Roman emperor Aurelian, however, regained Anatolia in 272 and razed Palmyra the following year.

The city remained the chief station on the strata Diocletiana, a paved road that linked Damascus to the Euphrates, but in 634 it was taken by Khālid ibn al-Walīd in the name of the first Muslim caliph, Abū Bakr. After that, its importance as a trading centre gradually declined.

The principal deity of the Aramaeans of Palmyra was Bol (probably an equivalent to Baal). Bol soon became known as Bel by assimilation to the Babylonian god Bel-Marduk. Both gods presided over the movements of the stars. The Palmyrenes associated Bel with the sun and moon gods, Yarhibol and Aglibol, respectively. Another heavenly triad formed around the Phoenician god Baal Shamen, the “lord of heaven,” more or less identical with Hadad. A monotheistic tendency emerged in the 2nd century CE with the cult of an unnamed god, “he whose name is blessed forever, the merciful and good.”

The ruins at Palmyra clearly reveal the network plan of the ancient city. Along the principal east-west street, named the Grand Colonnade by archaeologists, a double portico is ornamented with three nymphaea (nymph). To the south are the agora, the Senate House, and the theatre. Other ruins include a vast complex called Diocletian's Camp and the chief Palmyrene sanctuary, dedicated to Bel, Yarhibol, and Aglibol; a number of significant ancient Christian churches have also been uncovered. In architecture the Corinthian order marks almost all the monuments, but the influence of Mesopotamia and Iran is also clearly evident. In addition, art found on monuments and tombs reflects the influences of the surrounding Roman and Persian empires. The ruins of the ancient city of Palmyra were designated a UNESCO World Heritage site in 1980.