Plutarch, Cleomenes
Bernadotte Perrin, Ed.

14. To begin with, then, the Mantineians invited him to help them, and after he had made his way into the city by night, they expelled the Achaean garrison and put themselves in his hands. Cleomenes restored to them their laws and constitution, and on the same day marched away to Tegea. Then, shortly afterwards, he fetched a compass through Arcadia and marched down upon the Achaean city of Pherae. His desire was either to fight a battle with the Achaeans, or to bring Aratus into disrepute for running away and abandoning the country to him. For although Hyperbatas was general at that time, Aratus had the entire power in the Achaean league. [2] Moreover, after the Achaeans had marched out with all their forces and pitched their camp at Dymae, near the Hecatombaeum, Cleomenes came up against them. He did not think it well, however, to pitch his own camp between the city of Dymae, which was hostile, and the army of the Achaeans, and therefore boldly challenged the Achaeans and forced them to engage. He was completely victorious, routed their phalanx, slew many of them in the battle, and took many prisoners also. Then he went up against Langon, drove out the Achaean garrison, and restored the city to the Eleians.