Cheilon from Sparta.
From the Wikipedia: Chilon of Sparta (Χίλων or Χείλων; 6th century BC) was a Lacedaemonian and one of the Seven Sages of Greece. Chilon was the son of Damagetus, and lived towards the beginning of the 6th century BC. Herodotus speaks of him as contemporary with Hippocrates, the father of Peisistratus, and Diogenes Laertius states that he was an old man in the 52nd Olympiad (572 BC), and that he was elected of ephor in Sparta in the 56th Olympiad (556/5 BC). Alcidamas stated that he was a member of the Spartan assembly. Diogenes Laertius even goes so far as to claim that Chilon was also the first person who introduced the custom of joining the ephors to the kings as their counselors. Chilon is said to have helped to overthrow the tyranny at Sicyon, which became a Spartan ally. He is also credited with the change in Spartan policy leading to the development of the Peloponnesian League in the sixth century BC.