History of the Peloponnesian War
Thucydides
Thucydides. The history of the Peloponnesian War, Volume 1-2. Dale, Henry, translator. London: Heinemann and Henry G. Bohn, 1851-1852.
But it was for the war carried on at an early period between the Chalcidians and Eretrians, that the rest of Greece also was most generally divided in alliance with one side or the other.