The beginning of the siege of Mexico, then, lay in the struggles of the besiegers to obtain possession of the ditches, which were to be filled up, by levelling the ramparts. This was a work both of infinite danger and toil, the besieged fighting from behind the advanced barriers with unexampled resolution, and, however overpowered, never retreating beyond the ditch, until their companions had left but a single plank for their passage, which was immediately afterwards withdrawn. After this, the Spaniards were forced to overturn the first barrier into the chasm, before they could rush across the slough of mud and water, to attack the second; and all this was to be done not only against violent opposition in front, but with a most dangerous and audacious species of annoyance practised on one flank or the other, and sometimes on both. Wherever the shallows admitted, the Mexicans drove into the bottom of the lake, and at but a short distance from the dike, strong piles, to which they secured their canoes, furnished with high and thick bulwarks of planks, almost musket-proof; and from these they drove arrows, darts, and stones against the soldiers with destructive effect. Nay, with such wisdom had the young king of Mexico devised means to embarrass his adversary, that he had even secured his little flotillas from the possibility of approach, by sinking rows of piles in the lake, parallel with the causeways, through which the brigantines could not pass, to disperse them. It was to but little purpose that Cortes battered them from a distance with his falconets; the following morning saw replaced every loss of men and canoes. The soldiers were excited to fury by an annoyance so irritating, and some were found at times frantic enough to leap into the lake, where the waters happened to be sufficiently shallow, and endeavour to carry the flotillas, sword in hand. The narrowness and obstructed condition of the dikes making it impossible that all the forces could act upon them together, the vast multitudes of native allies were left in reserve, with the cavalry, on the shore,--where they were not idle, the numbers, as well as the boldness of the Mexicans being so great, that they frequently sent armies to the shore by night, who, at the dawn, fell upon the reserved troops with all the rancour of opponents in a civil war. This was the condition of the war at its commencement. The grand desiderata,--the removal of the flotillas, and the profitable employment of the confederates, were not effected until Cortes had seized all the piraguas of the shore-towns, and sent them, manned with Tlascalans, against the palisaded posts, where, besides doing what execution they could upon the enemy, the allies tore away the piles, and thus admitted some of the lighter brigantines among the canoes.