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.