The Spaniards and their allies have to…
July 1520 CE
The Spaniards and their allies have to flee the city, as the population of Tenochtitlan has risen against them and their situation can only deteriorate.
Because the Aztecs have removed the bridges over the gaps in the causeways that linked the city to the mainland, Cortés' men construct a portable bridge with which to cross the openings.
On the rainy night of July 10, 1520, the Spaniards and their allies set out for the mainland via the causeway to Tlacopan.
They place the portable bridge in the first gap, but at that moment their movement is detected and Aztec forces attack, both along the causeway and by means of canoes on the lake.
The Spanish are thus caught on a narrow road with water or buildings on both sides.
The retreat quickly turns into a rout.
The Spanish discover hat they cannot remove their portable bridge unit from the first gap, and so have no choice but to leave it behind.
The bulk of the Spanish infantry, left behind by Cortés and the other horsemen, has to cut their way through the masses of Aztec warriors opposing them.
Many of the Spaniards, weighed down by their armor and booty, drown in the causeway gaps or are killed by the Aztecs.
Much of the wealth the Spaniards have acquired in Tenochtitlan is lost.
The bridge is later called "Alvarado's Leap".
The channel is now a street in Mexico City, called "Puente de Alvarado" (Alvarado's Bridge), because it seemed Alvarado escaped across an invisible bridge.
(He may have been walking on the bodies of those soldiers and attackers who had preceded him, given the shallowness of the lake.)
It is said that Cortés, upon reaching the mainland at Tlacopan, wept over their losses.
This episode is called "La Noche Triste" (The night of sorrows), and the old tree ("El árbol de la noche triste") where Cortés allegedly cried is still a monument in Mexico.