During the Hellenistic period under the Seleucids (between 312 and 64 BC), Palmyra became a prosperous settlement owing allegiance to the Seleucid king.
Evidence for Palmyra's urbanisation in the Hellenistic period is rare; an important piece is the Laghman II inscription found in Laghman, modern Afghanistan, and commissioned by the Indian emperor Ashoka c. 250 BC.
The reading is contested, but according to semitologist André Dupont-Sommer, the inscription records the distance to "Tdmr" (Palmyra).
In 217 BC, a Palmyrene force led by Zabdibel joined the army of King Antiochus III in the Battle of Raphia which ended in a Seleucid defeat by Ptolemaic Egypt.
In the middle of the Hellenistic era, Palmyra, formerly south of the al-Qubur wadi, began to expand beyond its northern bank.
By the late second century BC, the tower tombs in the Palmyrene Valley of Tombs and the city temples (most notably, the temples of Baalshamin, Al-lāt and the Hellenistic temple) began to be built.
A fragmentary inscription in Greek from the Temple of Bel's foundations mentions a king titled Epiphanes, a title used by the Seleucid kings.

In 64 BC the Roman Republic conquered the Seleucid kingdom, and the Roman general Pompey established the province of Syria.
Palmyra was left independent, trading with Rome and Parthia but belonging to neither.
The earliest known inscription in Palmyrene is dated to around 44 BC; Palmyra was still a minor sheikhdom, offering water to caravans which occasionally took the desert route on which it was located.
However, according to Appian Palmyra was wealthy enough for Mark Antony to send a force to conquer it in 41 BC.
The Palmyrenes evacuated to Parthian lands beyond the eastern bank of the Euphrates, which they prepared to defend.
During the Hellenistic period under the Seleucids (between 312 and 64 BC), Palmyra became a prosperous settlement owing allegiance to the Seleucid king. Evidence for Palmyra's urbanisation in the Hellenistic period is rare; an important piece is the Laghman II inscription found in Laghman, modern Afghanistan, and commissioned by the Indian emperor Ashoka c. 250 BC. The reading is contested, but according to semitologist André Dupont-Sommer, the inscription records the distance to "Tdmr" (Palmyra). In 217 BC, a Palmyrene force led by Zabdibel joined the army of King Antiochus III in the Battle of Raphia which ended in a Seleucid defeat by Ptolemaic Egypt. In the middle of the Hellenistic era, Palmyra, formerly south of the al-Qubur wadi, began to expand beyond its northern bank. By the late second century BC, the tower tombs in the Palmyrene Valley of Tombs and the city temples (most notably, the temples of Baalshamin, Al-lāt and the Hellenistic temple) began to be built. A fragmentary inscription in Greek from the Temple of Bel's foundations mentions a king titled Epiphanes, a title used by the Seleucid kings.
In 64 BC the Roman Republic conquered the Seleucid kingdom, and the Roman general Pompey established the province of Syria. Palmyra was left independent, trading with Rome and Parthia but belonging to neither. The earliest known inscription in Palmyrene is dated to around 44 BC; Palmyra was still a minor sheikhdom, offering water to caravans which occasionally took the desert route on which it was located. However, according to Appian Palmyra was wealthy enough for Mark Antony to send a force to conquer it in 41 BC. The Palmyrenes evacuated to Parthian lands beyond the eastern bank of the Euphrates, which they prepared to defend.
Palmyra