Cleomenes III

Born around 260 BCE to King Leonidas II, Cleomenes III grew up in a Sparta hollowed by inequality and shrinkage of its citizen body. The memory of Agis IV—executed after a failed attempt to reset the laws—shaped his early world. Cleomenes married Agiatis, Agis’ widow, whose estates and convictions steered him toward reform. Patient, intense, and spare in habits, he studied both the Lycurgan ideals and the grim arithmetic of a polis with too few Spartiates to man the line.

By the mid-220s BCE Cleomenes pressed war against the Achaean League in the Peloponnese, a crucible in which he fused policy and sword. In 227 BCE he staged a revolution per policy: he abolished the ephorate—Sparta’s powerful board of magistrates—on charges of corruption, executed opponents, canceled debts, and parceled land into new citizen allotments. He enrolled fresh citizens, revived the agoge, and rearmed his hoplites with longer pikes in Macedonian fashion. The streets of Sparta filled again with boys in red cloaks, bare-foot and tough, a performative return to Lycurgus buttressed by modern drill. Victories followed—at Mount Lycaeum and Ladoceia—until the Achaeans, led by Aratus of Sicyon, invited Macedon’s Antigonus III Doson. In 222 BCE, at Sellasia, Cleomenes faced a coalition army larger and deeper than any Sparta had met in generations. His phalanx fought hard on the hills of Eva and Olympus, but numbers and cavalry told. Defeated, he fled to Egypt, where Ptolemaic politics caged him until a final failed rising ended in suicide in 219 BCE.

Cleomenes was both idealist and autocrat: gentle in private, ruthless in public necessity. He saw that without property reform Sparta would die on the vine; yet to push it through he cut down ancient offices and spilled civic blood. His character comes through in glimpses—a king who walked rather than rode, who slept little, who could joke with soldiers and terrify opponents. He earned loyalty from the poor and fear from the old guard, and he cherished Agiatis’ counsel to the end.

His significance in the dyarchy’s story is immense. Cleomenes proved that kingship could still act as a reforming engine, not merely a ceremonial generalship. But he also provoked the response that would doom Sparta’s independence: Macedonian intervention at Sellasia. In him the central question hardens—could law-bound kingship heal inequality without turning tyrannical or inviting foreign saviors? Cleomenes’ answer was brave and tragic: yes in vision, no in outcome. His fall cleared the path for later strongmen like Nabis and pushed Sparta from reformation to enforced settlement.