Ancient country in western Asia that was conquered by the Sassanid Dynasty in AD 226: At its height in the early 1st century BC, as the Parthian empire included the area between the Euphrates and Indus rivers and between the Amu Darya and the Persian Gulf. Parthians were famous as horsemen and archers. Parthian Empire was weakened by internal disorder and by conflict with Rome.See also the List of Parthian Kings under Parthian Dynasty. (Wikipedia) - Parthia This article is about the region of Parthia. For the empire ruled by Parthians, see Parthian Empire. For the thoroughbred racehorse, see Parthia (horse).Young man with Parthian costume. Palmyra, Syria, 1st half of the 3rd century AD. Decoration of a funerary stela. The Louvre.