Eurypontid

The Eurypontid refers to the members of one of the two royal houses of ancient Sparta, the other being the Agiad dynasty. Together, the Eurypontids and the Agiads formed Sparta’s dual monarchy, in which two kings ruled simultaneously and shared certain religious and military duties. Real political power was balanced by other institutions, including the Gerousia (council of elders), the Apella (assembly), and the ephors.

Traditionally, the two houses are said to have been established by twin brothers, Procles and Eurysthenes. The Eurypontid line claims descent from Eurypontos (or Eurypontus), and, like the Agiad line, is anchored in legendary ancestry that Spartans used to legitimize the monarchy.

In the classical period, Eurypontid kings are recorded as ruling alongside their Agiad counterparts and taking part in major campaigns and diplomacy. Early chronology is uncertain, since sources blend history and legend and the names and reign lengths of many early Eurypontid rulers are not reliably fixed.

From the late classical and Hellenistic periods onward, the two houses continued to provide kings, but royal power diminished in practice as authority shifted to other institutions and rulers. The Eurypontid line persisted as part of Sparta’s constitutional framework until the broader political shifts of later antiquity, after which the distinct royal houses ceased to exert independent authority. Modern scholarship relies on ancient authors such as Herodotus, Xenophon, and Pausanias, along with inscriptions, to reconstruct the dynasty’s history, though many details remain debated.