Plutarch, Cleomenes
Bernadotte Perrin, Ed.

7. After this, Cleomenes, being now greatly elated, and persuaded that if he could keep the control of things entirely in his own hands during the war with the Achaeans, he would easily obtain the mastery, began to instruct his mother's husband, Megistonoüs, that they must needs get rid of the ephors, put the property of the citizens into a common stock, and rouse and incite the Spartans, thus put upon their old footing of equality, to assume the supremacy in Greece. Megistonoüs was convinced, and enlisted in the cause two or three of his friends besides.

[2] Now, it came to pass about that time that one of the ephors, who was sleeping in the precinct of Pasiphaë, had an astonishing dream. He dreamed that in the place where the ephors were wont to sit for the prosecution of business, one chair only stood, but the other four had been taken away; and that in his amazement at this a voice came to him from the temple saying that this was better for Sparta. [3] This dream the ephor related to Cleomenes, who at first was much disturbed, and thought that the other had some suspicion of his design and was making trial of him; but when he was convinced that the relater spoke the truth, his courage revived. So taking all the citizens who, as he suspected, would be most opposed to his designs, he seized Heraea and Alsaea, two cities belonging to the Achaean league, introduced supplies of food into Orchomenus, and encamped by Mantineia, [4] from whence he made long marches up and down the land, and utterly wore out the Lacedaemonians, so that it was at their own request that he left most of them in Arcadia, while with his mercenaries he himself set out for Sparta. On the march he imparted his design to those whom he believed to be most favourably disposed to him, and went forward slowly, that he might fall upon the ephors while they were at supper.