The greatest ruling clans (Vispuhrs) of ancient Iran, at the time of Pa rthian dynasty, were traditionally seven families, and the two most pre dominant of them were the Suren and Karen, of the Ashkani (Arsacid) des cent, and bore the surname of Pahlav, [Parthian]. Suren-Pahlavs were t he member of Parni branch of the Aryan (Indo-Iranian) Stock, a member t ribe of the Dahae confederation, (Dahae-Parno-Parthian) tribes (chosen c hiefs for war and princes for peace) from among the closest circle of t he princely family. The Parnis were famous for their breeding of horses , for their combat cavalry, and for their fine archers. They have been a p eople who kept the traditions of patriarchal tribal organization. The S uren-Pahlavs alongside the other members of the Parni, with Arsaces at t heir head, took the province of Parthovia (Parthia) after having beaten A ndragoras and soon, neighboring Hyrcania was annexed and the Caspian re ached.