Parthia was an ancient empire of Asia, in what are now Iran and Afghanistan. They were excellent horsemen and archers. In battle, mounted parthians often discharged their arrows back toward the enemy while pretending to flee; this is the origin of the phrase “A Parthian Shot.” Parthia was subject successively to the Assyrians, Medes, Persians, and Macedonians under Alexander the Great, and Seleucids.
About 250 BC the Parthians succeeded in founding an independent kingdom. After the middle of the 1st century BC Parthia was a rival of Rome, and several wars occurred between the two powers. Phraates IV, king from 38 until 2 BC, had an early success in driving the Roman Marc Antony out of Parthia. After 31 BC, Phraates had to cope with a stubborn rebellion by one of his generals, who briefly usurped the throne. Phraates subsequently acknowledged his dependency to Rome. He died in a palace intrigue.