History of the Peloponnesian War

The Athenian armament had now crossed over from Lesbos to Chios, and being master by sea and land began to fortify Delphinium, a place naturally strong on the land side, provided with more than one harbour, and also not far from the city of Chios.

Meanwhile the Chians remained inactive. Already defeated in so many battles, they were now also at discord among themselves; the execution of the party of Tydeus, son of Ion, by Pedaritus upon the charge of Atticism, followed by the forcible imposition of an oligarchy upon the rest of the city, having made them suspicious of one another; and they therefore thought neither themselves nor the mercenaries under Pedaritus a match for the enemy.