History of the Peloponnesian War

Sitalecs then, being this man's son, the Athenians made their ally, wishing him to join them in conquering the Thrace-ward towns and Perdiccas.

So Nymphodorus came to Athens and concluded the alliance with Sitalces, and made his own son Sadocus a citizen of Athens, and undertook to bring to a close the war on the side of Thrace; for he said he would persuade Sitalces to send the Athenians a Thracian force of cavalry and targeteers.