History of the Peloponnesian War

After the Plataeans had finished their preparations, they waited for a night that was stormy with rain and wind and at the same time moonless, and then went forth. They were led by the men who were the authors of the enterprise. First they crossed the ditch which surrounded the town, then reached the foot of the enemy's wall unobserved by the guards, who in the all-pervading darkness could not see ahead and could not hear because the clatter of the wind drowned the noise of their approach;

and, besides, they kept a good distance apart as they advanced, in order that their arms might not rattle against each other and cause detection. And they were not only lightly armed but also had only the left foot sandalled, for security against slipping in the mud.