Plutarch, Pompey
Bernadotte Perrin, Ed.

37. In the fortress of Caenum Pompey found also private documents belonging to Mithridates, and read them with no little satisfaction, since they shed much light upon the king's character. For there were memoranda among them from which it was discovered that, besides many others, he had poisoned to death his son Ariarathes, and also Alcaeus of Sardis, because he had surpassed him in driving race-horses. [2] Among the writings were also interpretations of dreams, some of which he himself had dreamed, and others, some of his wives. There were also letters from Monime to him, of a lascivious nature, and answering letters from him to her. Moreover, Theophanes says there was found here an address of Rutilius, which incited the king to the massacre of the Romans in Asia. [3] But most people rightly conjecture that this was a malicious invention on the part of Theophanes, perhaps because he hated Rutilius, who was wholly unlike himself, but probably also to please Pompey, whose father had been represented as an utter wretch by Rutilius in his histories.