Cortés received a similar application from various other towns, which were disposed, could they do so with safety, to throw off the Mexican yoke. But he was in no situation to comply with their request. He now felt more sensibly than ever the incompetency of his means to his undertaking. “I assure your Majesty,” he writes in his letter to the emperor, “the greatest uneasiness which I feel, after all my labors and fatigues, is from my inability to succor and support our Indian friends, your Majesty’s loyal vassals.”[330] Far from having a force competent to this, he had scarcely enough for his own protection. His vigilant enemy had an eye on all his movements, and, should he cripple his strength by sending away too many detachments or by employing them at too great a distance, would be prompt to take advantage of it. His only expeditions, hitherto, had been in the neighborhood, where the troops, after striking some sudden and decisive blow, might speedily regain their quarters. The utmost watchfulness was maintained there, and the Spaniards lived in as constant preparation for an assault as if their camp was pitched under the walls of Mexico. On two occasions the general had sallied forth and engaged the enemy in the environs of Tezcuco. At one time a thousand canoes filled with Aztecs, crossed the lake to gather in a large crop of Indian corn, nearly ripe, on its borders. Cortés thought it important to secure this for himself. He accordingly marched out and gave battle to the enemy, drove them from the field, and swept away the rich harvest to the granaries of Tezcuco. Another time a strong body of Mexicans had established themselves in some neighboring towns friendly to their interests. Cortés, again sallying, dislodged them from their quarters, beat them in several skirmishes, and reduced the places to obedience. But these enterprises demanded all his resources, and left him nothing to spare for his allies. In this exigency, his fruitful genius suggested an expedient for supplying the deficiency of his means. Some of the friendly cities without the Valley, observing the numerous beacon-fires on the mountains, inferred that the Mexicans were mustering in great strength, and that the Spaniards must be hard pressed in their new quarters. They sent messengers to Tezcuco, expressing their apprehension, and offering reinforcements, which the general, when he set out on his march, had declined. He returned many thanks for the proffered aid; but, while he declined it for himself, as unnecessary, he indicated in what manner their services might be effectual for the defence of Chalco and the other places which had invoked his protection. But his Indian allies were in deadly feud with these places, whose inhabitants had too often fought under the Aztec banner not to have been engaged in repeated wars with the people beyond the mountains.