Cleomenes I. succeeded as one of the two joint kings about 519 b.c. He led a Spartan force to Athens in 510 to aid the Alcmaeonids and their followers in the expulsion of Hippias. He was called in subsequently to support the oligarchical party there, headed by Isagoras, against the party of Clisthenes. He forcibly expelled from the city, on a technical charge of pollution, no less than 7000 families, and established an entirely new constitution, transferring the government from the old senate to 300 of the oligarchical party. Eventually, however, he and his small force were blockaded by their opponents in the Acropolis, and forced to capitulate and to quit the city. On his return home he at once raised a force of Spartans and allies in order to avenge his failure, and to establish a despotism at Athens in the person of Isagoras. But when the expedition had reached Eleusis on its march, not only some of the subject-allies but also his brother-king Dem aratus (of the Proclid junior branch) refused to proceed further, and he had to return without effecting his object. When the Ionian colonies revolted from Persia, in 500, their leader Aristagoras came to seek aid from Sparta. Cleomenes was at first inclined to entertain the tempting offers of Asiatic conquest which the Ionian, in his eagerness to secure the alliance, laid before him. But when Aristagoras, in reply to his questions, was forced to confess-that Susa, the Persian capital, was no less than three months’ journey inland from the sea, the king was startled, and bade his visitor quit Sparta before sunset. The Ionian then tried to bribe him; and as his offers mounted higher and higher, his little daughter Gorgo, some eight or nine years old (afterwards the wife of Leonidas) said, “Father, go away, or the stranger will corrupt you.” Such at least is the story told by Herodotus, though Grote doubts its authenticity.

During a local war between Sparta and Argos, Cleomenes by a stratagem defeated the Argive forces near Tiryns. Those who escaped from the battle took refuge in a consecrated grove, which was set on fire by order of Cleomenes, and no less than 6000 men, the flower of the Argive citizens, are said either to have been killed in the battle, or to have perished in the flames,—a loss from which Argos was very long in recovering. For some reason he did not pursue his victory, but returned at once to Sparta, to the great dissatisfaction of his own people. One legend relates that the city of Argos was successfully defended against him by its women.

When Darius (491) sent heralds to demand the submission of all the Greeks, and the inhabitants of Aegina had. consented to give the tributary “earth and water,” Cleomenes proceeded to the island to punish its treachery to the national cause. His fellow-king Demaratus, who was always jealous of him, privately encouraged the Aeginetans in their resistance, and the feud between the two became so bitter, that Cleomenes brought up an old charge of illegitimacy against his colleague, and succeeded in driving him into exile. Retributive fate very soon overtook himself; he was convicted of having procured the deposition of Demaratus by tampering with the priestess of the Delphian oracle, and had to retire for safety into Thessaly, and thence into Arcadia. There he endeavoured to raise war against his countrymen, who in their alarm were weak enough to recall him. His renewed reign was not long. He soon after showed symptoms of madness, attacking violently with his staff those who came to him for audience. Some attributed this derangement to a habit of hard drinking which had grown upon him; others saw in it the just punishment of his impiety, both in his intrigues with the oracle at Delphi, and in the burning of the sacred grove at Argos and the massacre of those who had taken sanctuary there. At length he had to be placed in close confinement, when he persuaded the slave who had charge of him to bring him a knife, with which he deliberately slashed himself to pieces. *

Cleomenes III. the last of the Agid line, succeeded 240 b.c., —a king of strong and determined character, who wished to restore at Sparta the old constitution and discipline of Lycurgus, and to destroy the Achaean League. He met Aristomachus, the “captain” of the League, with a force of 5000 men against 25,000 at Palantium, but the Achaeans, even with this advantage, declined the engagement. The next year he defeated them in a great battle at the foot of Mount Lycaeum. He found active opponents at Sparta in the Ephors, whose anomalous authority he held to have been gradually usurped in derogation of the royal prerogative, affecting dangerously the independence of the kings, and which it was therefore his great object to crush. He succeeded in this at last by an unscrupulous coup d’etat, surrounding the hall in which the Ephors were feasting with a body of armed mercenaries, and slaughtering them on the spot. He met with no resistance from the panic-stricken citizens, and at once proceeded to inaugurate his new constitution, abolishing the Ephorate entirely, restoring the old prerogatives of the kings, and amongst other reforms making a re-distribution of lands, and extending the franchise.

He had still to contend with the Achaean League for the supremacy of Greece. In the war which ensued he was finally defeated by Antigonus of Macedonia, who had become virtually the master of the League, in the battle of Sellasia (222), when the death-blow was given to the independence of Sparta. Cleomenes took refuge in Egypt with Ptolemy Euergetes, who received him kindly. But the succeeding Ptolemy neglected and even imprisoned him. He escaped and attempted to head an insurrection against the king, failing in which, he committed suicide.