Cortés, impatient of delay, pressed forward without waiting for his answer, and found himself, September 2, 1519, before an army of Otomis, a tribe friendly to the Tlaxcallans, whom they had persuaded to attack the strangers, without mixing in the fight themselves. Cortés easily repulsed this savage band, and without pressing his advantage, again attempted negotiations with the republic; but by this time a haughty message was returned to him that "the strangers which the sea had thrown up could come if they chose to the great city, to become sacrifices to the gods and served up at a sacred festival." Cortés, of course, was firm, and on the 5th of September, 1519, took place the first real struggle between the army of the old world, which in this case appeared the new one, and the brave descendants of an ancient race.
The Tlaxcallans, led by the young and brave General Xicotencatl, fought bravely, but the result was in favor of the little band of Spaniards, after a hot contest of but four hours. The Tlaxcallans returned to their city, and consulted their oracle. The head priest pronounced that their enemies were children of the sun, and invincible during the day, while their father was shining in the sky, but that by night they would lose their strength and be like other mortals.
The next night, encouraged by this divine decree, an attack was made, but Cortés was on his guard. The enemy, who, relying on their priests, had imagined they were marching to certain victory, took flight, in abject terror.
After this, the Tlaxcallans made no further resistance. Peace was solemnly concluded, and the republic recognized as a vassal to the crown of Castile, pledging itself to sustain Cortés in all his expeditions. Mass was celebrated, and the conclusion of the treaty was an occasion of great joy. This alliance was absolutely important to Cortés. The Tlaxcallans remained to the end faithful to it; later on, without their support, and their chief city to fall back upon, the conqueror must have inevitably failed in his enterprise.
The Tlaxcallans consented to accept the God of the Christians, but were unwilling to give up their old protecting divinities for fear of appearing ungrateful to them. Cortés insisted upon the abolition of human sacrifices, and himself made a chapel in the palace assigned to him and erected in it the cross. The first mass celebrated there attracted immense crowds, and many natives, especially young girls of good birth, were voluntarily baptized.
The Conquistadores entered Tlaxcalla the 22d of September, receiving demonstrations of the greatest friendship. Here Cortés rested awhile, but only in order to cement his good relations, and to obtain information how best to proceed. He himself is said to have been so ill from fever that he could hardly keep his seat in the saddle, but this man of iron habitually disregarded the troubles of the flesh.
His next step was to Cholula, where he was received with apparent cordiality; but Malintzi's vigilance discovered a plot for the destruction of the Spanish army. Cortés resolved to punish this treachery by an example. He collected all the principal Cholultecas in a large court, accused them of perfidy, and, without listening to explanations, put them to general slaughter, so that "in two hours," according to the letter of Cortés describing the affair, "perished more than three thousand natives." The body of the Tlaxcallans who had joined themselves to this expedition, gathered rich booty from it, and returned home well content with the prowess of their new ally.
Cortés then issued a general pardon. Calm returned to the streets of Cholula, and the people of the surrounding villages poured in to do honor to the terrible conqueror. Emissaries from Mexico, who witnessed this bloody triumph, were not slow to describe it to their sovereign, who became more and more frightened and despairing.
Cortés stayed two weeks in Cholula, before setting out again for Mexico. It was thus early that he received overtures of alliance from Ixtlilxochitl, king of a portion of Texcuco, who was in constant warfare with his brother Cacamatzin. These young men, it will be remembered, were nephews of Montezuma, who, in the quarrel between them had defended the cause of Cacamatzin, so that the neglected brother detested him. Like all the rest of Montezuma's kindred who played into the hands of his enemy, Ixtlilxochitl had later reason to regret his hasty recognition of the stranger, who came to seize and adopt for his own every thing, regardless of small quarrels and petty animosities. This early alliance with one of the neighboring chiefs was of great advantage to Cortés though he scarcely understood then its importance.
Ixtlilxochitl sent ambassadors as far as Tlaxcalla to invite Cortés to pass through his territory on his way to Mexico. Cacamatzin, on the other hand, indignant at the disregard shown to the wishes of his royal uncle by the Europeans, hastened to Texcuco, resolved to collect an army and declare war against them, but Montezuma, with a faithlessness not to be excused by his terror, himself set an ambuscade for his nephew, and handed him over to Cortés, who had him loaded with chains and imprisoned.