The Dahae Confederation of Parthia
The Sassand Dynasty, like the Achaemenid, originated in the province of Persis (Fars). Nominally, Fars is the original homeland of the Persian people, Hellenized- Parsi. The Sassanids saw themselves as successors of the Achaemenids, after the Hellenistic and Parthian interlude, and believed that it was their destiny to restore the greatness of Persia. The Sassanid empire installed a royal prince, this prince was called Gilanshah (King of Gils). There is scant evidence about the relationship between local Gil and Deylami chieftains and the Sassanid empire.
During the 5th to 3rd centuries B.C. the Scythians evidently prospered. When Herodotus wrote his Histories in the 5th century BC, Greeks distinguished a 'Greater Scythia' that extended a 20-day ride from the Danube River in the west, across the steppes of today's Ukraine to the lower Don basin, from 'Scythia Minor'. The Don, then known as Tanaïs, has served as a major trading route ever since. The Crimean Scythians created a kingdom extending from the lower Dnieper to the Crimea. Their capital city, Scythian Neapol, stood on the outskirts of modern Simferopol. (The Goths destroyed it much later, in the 5th century AD.)
In the southeasternmost corner of the plains, north of the woods of Thrace, Philip II of Macedon settled Macedonian trading towns along routes as far north as the Danube during the 330s BC. Shortly after 300 BC, the Celts seem to have displaced the Scythians from the Balkans, while in south Russia a kindred tribe, the Sarmatians.
The Parni were unknown before the 3rd century BCE; a member tribe of the Dahae confederation, (Dahae-Parno-Parthian) tribes, the Parni were originally a nomad tribe of the Central Asian steppes, which was the home of Iranian nomadic tribes for centuries, such as the Scythians, Saka, and Sarmatians. Being nomads, they roamed across the plains, incidentally attacking the urbanized countries to the south, east and west. Their language was from Sacian (Indo-Iranian) family, closely related to Scythian and Median.
Celts began to migrate south into the Mediterranean areas, France, and Spain-Gaulish Britain.
In ancient Chinese the name for Parthia was "Anxi," pronounced anshiak in Tang dynasty Chinese. Diodotus, governor for the Bactrian territory, asserted independence in 250 B.C. to form the Greco-Bactrian kingdom. This kingdom was characterized by a rich Hellenistic culture, and was to continue its domination of Bactria until around 125 BC, when it was overrun by the invasion of northern nomads. One of the Greco-Bactrian kings, Demetrius I of Bactria, invaded India around 180 B.C. to form the Greco-Indian kingdom, lasting until 1 BC. The Hellenistic lands in Asia after the death of Alexander were ruled by the Seleucid Empire; an overextended domain, which neglected its Persian possessions in favour of Anatolia and Syria.
In Akkadian, the Saka were called the Ashkuza and were closely associated with the Gimirri, who were the Cimmerians known to the ancient Greeks.
The first of the Parnis Ashk or Arakhsh (Arsaces) had himself crowned in the city of Asaak, and the tribe took the name of the Parthians, their close relatives, a name that meant "exiled." The country where they lived, along the river Syr Darya (Jaxartes), was occupied by the tribe that the Persians knew as the Dahae or Dahâ. It is likely that this tribe disintegrated after the fall of the Persian Empire; the new rulers, the kings of the Seleucid dynasty, were never able to control the country of what is now Mazandaran, Uzbekistan and Turkmenistan. first Parthian king, Arsaces, is said to have been of Parnian origin. Armenian chronicles identify this nation as White Huns. Arsaces was king of Armenia c. 34–35.