Pausanias 3.6.2

Agesipolis, the elder of the sons of Cleombrotus, is not a striking figure in history, and was succeeded by his younger brother Cleomenes. His first son was Acrotatus, his second Cleonymus. Acrotatus did not outlive his father, and when Cleomenes afterwards died, there arose a dispute about the throne between Cleonymus the son of Cleomenes and Areus the son of Acrotatus. So the senators acted as arbitrators, and decided that the dignity was the inheritance of Areus the son of Acrotatus, and not of Cleonymus.

Deprived of his kingship Cleonymus became violently angry, and the ephors tried to soothe his feelings by bestowing upon him various honors, especially the leadership of the armies, so as to prevent his becoming one day an enemy of Sparta. But at last he committed many hostile acts against his fatherland, and induced Pyrrhus the son of Aeacides to invade Laconia.

While Areus the son of Acrotatus was king in Sparta, Antigonus the son of Demetrius attacked Athens with an army and a fleet.3 To the help of the Athenians there came the Egyptian expedition with Patroclus, and every available man of the Lacedaemonians with Areus their king at their head.