Besides, the transport of provisions from Euboea, which had before been carried on so much more quickly over land by Decelea from Oropus, was now effected at great cost by sea round Sunium; everything the city required had to be imported from abroad, and instead of a city it became a fortress. Summer and winter the Athenians were worn out by having to keep guard on the fortifications, during the day by turns, by night all together, the cavalry excepted, at the different military posts or upon the wall. But what most oppressed them was that they had two wars at once, and had thus reached a pitch of frenzy which no one would have believed possible if he had heard of it before it had come to pass. For could any one have imagined that even when besieged by the Peloponnesians entrenched in Attica, they would still, instead of withdrawing from Sicily, stay on there besieging in like manner Syracuse, a town (taken as a town) in no way inferior to Athens, or would so thoroughly upset the Hellenic estimate of their strength and audacity, as to give the spectacle of a people which, at the beginning of the war, some thought might hold out one year, some two, none more than three, if the Peloponnesians invaded their country, now seventeen years after the first invasion, after having already suffered from all the evils of war, going to Sicily and undertaking a new war nothing inferior to that which they already had with the Peloponnesians? These causes, the great losses from Decelea, and the other heavy charges that fell upon them, produced their financial embarrassment; and it was at this time that they imposed upon their subjects, instead of the tribute, the tax of a twentieth upon all imports and exports by sea, which they thought would bring them in more money; their expenditure being now not the same as at first, but having grown with the war while their revenues decayed.