History of the Peloponnesian War
Thucydides
Thucydides. History of the Peloponnesian War. Crawley, Richard, translator. London and Toronto: J. M. Dent and Sons Ltd.; New York: E. P. Dutton and Co., 1914.
besides which they kept a good way off from each other, that they might not be betrayed by the clash of their weapons. They were also lightly equipped, and had only the left foot shod to preserve them from slipping in the mire.
They came up to the battlements at one of the intermediate spaces where they knew them to be unguarded: those who carried the ladders went first and planted them; next twelve light-armed soldiers with only a dagger and a breastplate mounted, led by Ammias, son of Coroebus, who was the first on the wall; his followers getting up after him and going six to each of the towers. After these came another party of light troops armed with spears, whose shields, that they might advance the easier, were carried by men behind, who were to hand them to them when they found themselves in presence of the enemy.