longer paid their annual tribute, but engaged in plots against the king and were ready to defy him by force of arms should he interfere with their rights. Disorganization within the empire, not force of arms, opened the way for the Roman legions into Mesopotamia. Nevertheless, the plundering of great commercial centers and royal treasures, as well as losses in man power and territory occasioned by the wars with Rome, greatly contributed to the decline of Parthia.
In the last years of the empire the name "Arsaces" became but a shuttlecock, bandied back and forth by claimants who possessed little if any real power. Under such conditions a strong leader backed by a powerful army had little difficulty in overcoming the disunited efforts of the nobles, many of whom must have longed for another strong central authority which should restore peace and prosperity. The Parthians had originally been alien to both Iran and Mesopotamia; their conquerors the Sasanidae came from Persis, where the ruined cities and the tombs of the great Achaemenid monarchs were a constant reminder of former Iranian glories. Ardashir, first of the new dynasty, found it no difficult task to overthrow the tottering and decrepit Arsacid line and thus to write the last chapter in the political history of Parthia.
