Arsacid

Arsacid, or Arsacids, is the name of the ruling dynasty that originated with Arsaces I and came to dominate the Parthian Empire and its successor states in late antiquity. The name means “descendant of Arsaces” and the family trace its legitimacy to a Parthian chieftain who led a rebellion against the Seleucid empire in the mid-3rd century BCE, establishing an independent Parthian state.

The Arsacids governed a large, multi-ethnic realm centered in northern Iran and Mesopotamia. Over centuries their rulers expanded Parthian authority, adopting the title of King of Kings and overseeing a largely feudal system in which semi-autonomous noble houses and client kings managed local governance. The dynasty’s capitals shifted over time, with important locations including Nisa, Hecatompylos, and later Ctesiphon. Parthian rule was marked by a competing diplomacy with Rome, frontier conflicts, and a policy of flexible alliances with Armenian and Caucasian client rulers.

The dynasty endured until 224 CE, when Ardashir I founded the Sasanian Empire and overthrew the last Arsacid ruler, Artabanus IV, ending Parthian sovereignty. The Arsacid legacy extended beyond Parthia; branches of the family provided ruling dynasties in other regions, most notably the Arsacid dynasties that ruled Armenia and parts of the Caucasus, and their name remains attached to both historical and regional monarchies associated with Parthian influence.