Cleomenes III, c.260–219 B.C., king of Sparta (235–221 B.C.). He was probably the most energetic king Sparta ever had, a conscious imitator of Agis III (see under Agis Agis I, fl. late 10th cent. B.C., was the traditional founder of the Agiad dynasty, one of the two ruling dynasties of Sparta, which had a dual kingship. The other dynasty, the Eurypontids, fathered the succeeding Agises.

Agis II, d. 398? B.C.
..... Click the link for more information. ). In his determined effort to restore the prestige of the city, he began (227 B.C.) a war against the Achaean League Achaean League (əkē`ən), confederation of cities on the Gulf of Corinth.
..... Click the link for more information. and was successful in many battles. At home his reforms were revolutionary: the kingship was made the supreme power, the ephorate was abolished, and the citizenship was widely extended, apparently to decrease the danger of discontent and to ally the people with the king. Cleomenes came to his downfall suddenly in 222 B.C. (or possibly 221 B.C.) when the Achaean League, allied with Antigonus III Antigonus III (Antigonus Doson) (ăntig`ənəs dō`sŏn,–sən), d. 221 B.C., king of Macedon.
..... Click the link for more information. of Macedon, routed the Spartan army. Cleomenes fled to Egypt to the protection of his patron, Ptolemy III. Imprisoned by Ptolemy's successor, he escaped, but, failing in an attempt to stir up a revolt in Alexandria, he committed suicide.

Cleomenes III

(died 219 BC) Agiad Spartan king (r. 235–222). Seeking to institute social reforms, in 227 he canceled debts, redistributed land, and restored the training of youth. He abolished the ephors and introduced the patronomoi (board of six elders). His early attempts to weaken the Achaean League (from 229) were successful, but in 222 his army fell at Sellasia to a Macedonian force summoned by the league. He fled to Egypt, where he was imprisoned but escaped (219); having failed to stir up revolt in Alexandria, he committed suicide.