Cortez now learned the reason of the rising of the Mexicans. It was the result of a hideous act of treachery, on the part of Alvarado. In the month of May was the great festival of the war god, which was held in his great temple; and the caziques asked permission of Alvarado to use, for the day, that portion which had been handed over to the Spaniards. He agreed to the request, on the condition that the Aztecs should celebrate no human sacrifices, and should come unarmed. At least six hundred nobles attended, in their most gorgeous robes, and Alvarado and his soldiers were present as spectators. While the Aztecs were employed in a religious dance, Alvarado gave the signal, his men rushed upon them with their arms, and every one of them was massacred unresistingly, not a single soul escaping. Various motives were assigned for this most foul massacre. Some writers have ascribed it solely to the desire for plunder; others to the desire of Alvarado to strike a blow that would intimidate the Mexicans from making any insurrectionary movement. Alvarado himself declared that he had information that the Mexicans intended to rise, but he gave no proofs, whatever, to justify his suspicions. The affair, indeed, seems to have been utterly indefensible, and must ever remain a foul blot upon Spanish honor. Cortez was extremely angry at hearing what had taken place and, after listening to Alvarado's explanation, said: "You have done badly. You have been false to your trust! Your conduct has been that of a madman!" It was, however, no time for quarrels; and as it was the impolicy of the deed, rather than its treachery, that angered Cortez, he speedily forgave the offender, who was one of the most popular officers in his army. The blow Alvarado had struck had a contrary effect to that which he had expected of it. No sooner had the news of the massacre spread through the city than the whole population rose, and at dawn next morning they attacked the palace, with desperate fury. Volumes of missiles were poured upon the defenders. The walls were assaulted, and the works set on fire, and the palace might have been taken had not Montezuma, yielding to the entreaties--and perhaps threats--of the garrison, mounted the walls, and urged the people to desist from the attack, as his own safety would be imperiled did they continue it. They obeyed him as usual, and withdrew from the assault; but threw up works round the place, and proceeded to starve the Spaniards out. The latter had considerable stores of food, but suffered severely from thirst until they were fortunate enough to discover a spring, and were thus enabled to hold out until the arrival of Cortez.