of the Agiad and Eurypontid families, both supposedly descendants of Heracles and equal in authority, so that one could not act against the power and political enactments of his colleague. The duties of the kings were primarily religious, judicial, and military. As chief priests of the state, they maintained communication with the Delphian sanctuary, whose pronouncements exercised great authority in Spartan politics. In the time of Herodotus c. 450 BC, their judicial functions had been restricted to cases dealing with heiresses, adoptions and the public roads. Aristotle describes the kingship at Sparta as "a kind of unlimited and perpetual generalship" (Pol. iii. 1285a), while Isocrates refers to the Spartans as "subject to an oligarchy at home, to a kingship on campaign" (iii. 24). Civil and criminal cases were decided by a group of officials known as the ephors, as well as a council of elders known as the Gerousia. The Gerousia consisted of 28 elders over the age of 60, elected for life and usually part of the royal households, and the two kings. High state decisions were discussed by this council, who could then propose policies to the damos, the collective body of Spartan citizenry, who would select one of the alternatives by vote. Royal prerogatives were curtailed over time. From the period of the Persian wars, the king lost the right to declare war and was accompanied in the field by two ephors. He was supplanted by the ephors also in the control of foreign policy. Over time, the kings became mere figureheads except in their capacity as generals. Political power was transferred to the ephors and Gerousia. An assembly of citizens called the Ekklesia was responsible for electing men to the Gerousia for life. Citizenship The Spartan education process known as the agoge was essential for full citizenship. However, usually the only boys eligible for the agoge were Spartiates, those who could trace their ancestry to the original inhabitants of the city. There were two exceptions. trophimoi or "foster sons" were foreign students invited to study. The Athenian general Xenophon, for example, sent his two sons to Sparta as trophimoi. Also, the son of a helot could be enrolled as a syntrophos if a Spartiate formally adopted him and paid his way; if he did exceptionally well in training, he might be sponsored to become a Spartiate. Spartans who could not afford to pay the expenses of