Agiad

The Agiad dynasty, or Agiad kings, was one of the two hereditary royal houses of ancient Sparta, the other being the Eurypontid dynasty. According to ancient tradition, the two houses descended from the twin grandsons Eurysthenes and Procles, the mythic founders of the Spartan monarchy; the Agiad line is named after Agis I, its legendary eponym. The two kings, one from each house, ruled jointly over Sparta, sharing military command and political authority, while performing religious duties and representing the city-state in ceremonies.

Notable Agiad rulers include Leonidas I, famed for his leadership at the Battle of Thermopylae during the Persian Wars; Agis II, who reigned during much of the Peloponnesian War; Agis III, who attempted reform and liberation of the Greek cities; and Agis IV, known for his attempts at restoring land distribution and redefining citizenship. The Agiads, like their Eurypontid counterparts, held the kingship alongside a powerful Gerousia and the Ephorate, and often faced checks on monarchical power from these institutions.

The dynasty's influence remained central to Sparta's politics for centuries but waned as Spartan power declined in the late classical and Hellenistic periods. The Agiad line persisted in name into later eras, but the role of the kings became largely ceremonial under broader political currents and foreign domination. The Agiad kings are a key subject in studies of ancient Spartan government and royal ideology.