So Philip then sent Hipponicus, one of his generals, to destroy the walls of Porthmus, the harbour for Eretria, and to set up Hipparchus, Automedon and Cleitarchus as tyrants.
[2] The tyrants, however, were not willing to keep their power quietly, for Demosthenes[3] mentions two separate forces sent by Philip for their support, under Eurylochus and Parmenion, respectively.
Aeschines says that a talent from Cleitarchus was part of the bribe which he alleges that Demosthenes received for procuring the decree in question.
Cleitarchus may have thought that it was in his interests to join the plan as a means of getting rid of the remnant of Athenian influence in Eretria.
The plan, however, seems to have collapsed, and in 341 BC, Demosthenes carried a decree for an expedition to Euboea with the view of putting down the Macedonian interest on the island.