Thrasybulus () was the tyrant of Miletus in the 7th century BC. Under his rule, Miletus fought a lengthy war against Lydia. This war ended without a decisive victor (a result that Herodotus credits to Thrasybulus's tricking Alyattes into making peace.Herodotus The Histories, 1.20-23f). Following the war, Miletus and Lydia concluded an alliance.
Thrasybulus was an ally of Periander, the tyrant of Corinth. He features in a famous anecdote from Herodotus's Histories,Herodotus The Histories, 5.92f in which a messenger from Periander asks Thrasybulus for advice on ruling.Aristotle tells the same story albeit with reversed roles (Thrasybulus asks Periander) in Politics, 3, 1284a and Politics, 5, 1311a Thrasybulus, instead of responding, takes the messenger for a walk in a field of wheat, where he proceeds to cut off all of the best and tallest ears of wheat. The message, correctly interpreted by Periander, was that a wise ruler would preempt challenges to his rule by "removing" those prominent men who might be powerful enough to challenge him.
Notes
References Fine, John V.A. The Ancient Greeks: A critical history (Harvard University Press, 1983)