History of the Peloponnesian War

Indeed through fear of their youth and great numbers, they even perpetrated the following deed: (for at all times most of the Lacedaemonian institutions were framed particularly with a view to the Helots, to guard against them.) They made proclamation, that as many of them as claimed to have done the state most service against the enemy should be picked out, professing that they would give them their liberty; thus applying a test to them, and thinking that those who severally claimed to be first made free, would also, through their high spirit, be most ready to attack them.

Having thus selected as many as two thousand, the Helots crowned themselves, and went round to the temples, on the strength of having gained their freedom; but the Spartans soon after did away with them, and no one ever knew by what means they were severally dispatched. And on this occasion they eagerly sent away seven hundred of them with Brasidas as heavy-armed troops:

the rest of his army he induced by pay to follow him from the Peloponnese. As for Brasidas himself, it was chiefly at his own desire that the Lacedaemonians sent him out.