Titus Livius (Livy), The History of Rome, Book 31
Evan T. Sage, Ph.D. Professor of Latin and Head of the Department of Classics in the University of Pittsburgh, Ed.

23. Exiles from Chalcis, driven out by the violence of Philip's garrison, brought the news that Chalcis could be captured without any opposition: [2] for the Macedonians, because there was no fear of an enemy near by, were straggling about the country, [p. 67]and the citizens likewise, trusting in their Macedonian¹ garrison, were careless in their guarding of the city. [3] Acting on this information, Claudius started out, and although he reached Sunium so early that he could have made the opening of the Euboean straits, he held his fleet at anchor until night-fall, lest he be seen after rounding the promontory; at dusk he moved, and after a calm voyage reached Chalcis a little before daybreak. [4] With a few soldiers using scaling ladders, he captured the nearest tower and the adjoining wall in a thinly-populated section of the city, the sentinels being found in some places asleep, in others absent from their posts. [5] The Romans then advanced to the centre of the city, and killing the guards and breaking down the gates they admitted the rest of their forces. [6] Thence they scattered throughout the town, the confusion being further increased by a fire which broke out in the buildings around the forum. [7] Both the royal granaries and the arsenal were burned, with a great store of munitions and artillery. Indiscriminate slaughter of fugitives and fighting men followed. [8] When there was no longer anyone of military age who had not perished or fled, Sopater the Acarnanian, commander of the garrison, having fallen, all the booty was first collected in the forum and then loaded on the ships. The prison also was broken open by the Rhodians, who released the captives whom Philip had confined there, thinking they would be in safest custody. [9] The king's statues were then thrown down and broken up, and when the recall was sounded the Romans embarked and returned to Piraeus, whence they had set out. [10] But if the Roman force had been large enough, so that they could [11] have held Chalcis without [p. 69]abandoning the defence of Athens, this event would² have been an auspicious beginning of hostilities: Chalcis and the Euripus would have been lost to the king, for as on the land the pass of [12] Thermopylae is the gateway to Greece, so by sea is the strait of Euripus.