According to the dialogue, the brothers were born on the Aegean island of Chios before relocating as colonists to Thurii in Magna Graecia of modern-day Italy.
According to Socrates in the Euthydemus, the two taught fighting in armor and legal oration before developing an interest in sophistry.
[4] Additionally, an individual named Dionysodorus appears in Lysias' Against Agoratus speech,[5] who potentially matches the sophist on several biographical details.
[2] Throughout the Euthydemus, Plato depicts Dionysodorus and his brother employing a string of logical fallacies against Socrates and his student Clinias (III), son of Axiochus.
"[7][8][9] In Xenophon's Memorabilia, Socrates examines a student of Dionysodorus who appears not to have learned basic elements of generalship.