History of the Peloponnesian War

When they heard this, they were ready at first to have fallen upon the chief authors of the oligarchy and upon such of the rest as were partakers of it. Yet afterwards, being hindered by such as came between and advised them not to overthrow the state, the enemy lying so near with their galleys to assault them, they gave it over.

After this, Thrasybulus, the son of Lycus, and Thrasyllus (for these were the principal authors of the change), determining now openly to reduce the state at Samos to a democracy, took oaths of all the soldiers, especially of the oligarchicals, the greatest they could devise, both that they should be subject to the democracy and agree together and also that they should zealously prosecute the war against the Peloponnesians, and withal be enemies to The Four Hundred and not to have to do with them by ambassadors.

The same oath was taken by all the Samians that were of age; and the Athenian soldiers communicated with them their whole affairs, together with whatsoever should succeed of their dangers; for whom and for themselves, they made account there was no refuge of safety; but that if either The Four Hundred or the enemy at Miletus overcame them, they must needs perish.