It became apparent to Cortés that his position was no longer tenable, and he resolved upon retreat. To remain was certain death; to retreat was fraught with danger; but there was a chance for some to escape with their lives. In pursuance of this intention, he ordered frequent sallies from the palace into the great square, and along the causeway leading to Tacuba. Many houses bordering the causeway were burned and the gaps caused by the removal of the bridges were filled with their debris. These gaps, however, were immediately reopened as soon as the Spaniards had retired, and Cortés found himself foiled at every point. It was evident that not only were the Aztecs superior in numbers, but also in strategy, for they had, by a subterfuge, obtained possession of their high-priest, or teoteuctli  (who had been taken prisoner in the fight at the temple), and with his aid had crowned Cuitlahuatzin king. He was the next in succession; but Cortés had aimed at placing either a son or nephew of Montezuma upon the throne, and was greatly chagrined at his double defeat.

The Mexicans gave the Spaniards two days more to live, threatening at the end of that time to carry their fortress by assault, at whatever cost of life to them. Their numbers were increased by accessions from outside the capital, and their repeated attacks were as vigorous as at first; while the Spaniards were already weak from hunger and half dead from exhaustion, being compelled to constant vigilance, without time for rest or sleep. Within two days of Montezuma's demise, preparations were hurried forward for departure. The causeway leading to Tacuba was selected as the route of retreat, being the shortest road to the mainland. As all the bridges across its canals had been destroyed, Cortés ordered a pontoon of wood to be constructed, which was placed in charge of fifty picked soldiers, all bound by oath to die rather than desert it, and 400 Tlascalans. There were three canals, and (as the sequel showed) three pontoons should have been provided. But for this oversight, hundreds of lives might have been saved, which were lost on the night of the retreat. Another mistake, and the greatest of all, was the choosing of night-time for retiring from the city. This was contrary to the dictates of military strategy, and was owing to superstition, which, as we know, was rife among that band of fanatical Spaniards.

It was just before midnight, July 1st, that the palace gates were thrown open and the little army emerged to begin the perilous passage of the causeway. The vanguard was in command of Sandoval, whose courage had often been tried; the rear-guard was under Alvarado and Velasquez de Leon, both valiant soldiers; while the centre was in charge of Cortés, who had a general supervision of the whole. They crossed the plaza in safety, but not in silence, owing to the rumble of the artillery and the clang of iron hoofs on the pavement. Still, no Aztecs showed themselves, and they were beginning to hope for a safe departure by the time the first canal was reached. Here the pontoon was fixed in position, and was safely crossed by the vanguard, the artillery, the first division of Tlascalans, the officials in charge of the king's gold, the prisoners, and most of the baggage.

Before departure, Cortés had divided Montezuma's treasure, intrusting the "king's fifth" to the proper officers, and had then given permission to his soldiers to carry off the remainder, at the same time warning them of the danger they incurred in assuming too large a burden. The avarice of many tempted them to lade themselves with the treasure, and few of these escaped the perils of that night of disaster.

It was while the bridge was being placed across the first canal that the Aztecs made their enemies aware that their movements were observed. The alarm was given by sentinels stationed at the canal, and taken up by the priests watching on the teocalli, who proclaimed it to all the people by blowing horns and sounding the great drum of serpent-skin above the war-god's altar. "Tlaltelulco! tlaltelulco!"  they shouted. "Out with the canoes; for the teules  are going; they are going; attack them at the canals!" Instantly, as though they had been evoked by enchanters' wands, arose most fearful apparitions on every side: from the lake, from canoes, from the canal, hurrying from the city streets; and a hail-storm of stones, arrows, darts, and burning-brands fell upon the heads of that devoted band huddled on the narrow causeway.

The vanguard dashed forward, only to be halted by the second canal; the rear-guard made the best resistance possible, but it was overwhelmed by the multitude of its enemies; and between these two divisions were crowded cavalry, infantry, Tlascalans, prisoners, artillery—a confused, disorganized mass—the animate portion of which was completely at the mercy of the infuriated Aztecs, who slaughtered at will, and sated to the full their craving for blood and revenge.

The pontoon was so wedged in position that it could not be moved, so the second canal was crossed without it. How, none but the great All-seeing One can tell. The Spaniards knew not how they got across—such few as escaped—but it was mainly upon the corpses of slain men and horses, mingled with maimed and dying comrades, artillery, treasure-boxes, and the like. At the third canal it was the same, except that the horrible bridge was composed of human corpses, mostly, and the writhing bodies of the wounded.

And on every side the gloating, fiercely exultant Aztecs were hewing at the defenceless throng with their great obsidian broad-swords, piercing the shrinking prisoners and the raging soldiers alike with lances, showering upon them darts, arrows, stones—every sort of missile-weapon they could lay their hands to, in the darkness of that terrible night.

They who were killed outright met the most merciful fate, for it was reserved for those who were made prisoners, whether wounded or not, to be sacrificed before the terrible war-god. After the first alarm was given, the great serpent-drum was silent for a space; then its horrifying boom resounded again above all other sounds, at intervals, giving notice that upon the Sacrificial Stone was stretched a prisoner, whose palpitating heart was that instant being torn from his breast. This assurance spurred on the Aztecs to fierce energy, and the causeway was enclosed between double and triple ranks of canoes, into which were dragged such victims as could be reached, who were instantly hurried off to the temple of sacrifice.

Imagine all these dreadful scenes transpiring on a night of pitchy darkness, made more miserable (if that were possible) by a drizzling rain, from the mists of which above the surrounding lake emerged those demoniac figures, which slashed and slew, and disappeared again with shrieking prisoners in their grasp. What wonder that the terrors of that night of black despair have survived through centuries of change in Mexico, and that ever since they have served to recall the vengeance of the Aztecs. The retreat of the "sorrowful night"—la noche trisle—has long since passed into history; but traditions of its terrors still remain with the people of Mexico.

In the little village of Popotla, near to Tacuba, still stands a venerable cypress-tree, a giant of a gigantic family, beneath which, it is said, Cortés sat awhile, in the gray dawn of the morning succeeding to that awful night, and wept over the loss of his army.

Most of the vanguard escaped, some of the centre, and among them their commander, and finally a few of the rear-guard; but fully one-third the Spanish force had been destroyed, or more than 500; 4000 Tlascalans, and all the prisoners, included among the latter being three children of Montezuma, Cacamatzin, and several caciques of note. Among those who escaped were the interpreters, Aguilar and Malinché, who were saved as if by a miracle, and Alvarado, who came limping along with the aid of his lance, having lost his horse, and also his comrade of the rear-guard, the gallant Velasquez de Leon.

The survivors of the noche triste  escaped only with their lives, almost everything else having been lost; all the artillery and ammunition, all the baggage, including vast treasure of gold in bars and priceless all but twenty-three of the horses, and even all the muskets, or arquebuses, which the despairing soldiers had thrown away in their frenzied flight.

Theirs was a "dreadful deliverance," indeed; nor were they safe even when they had reached the main-land, for a long and weary journey lay before them to Tlascala, a land of doubtful refuge and security. The courage of Cortés had not failed him in any emergency, even though his judgment had been at fault, and the fact that he was among the first to arrive at Tacuba was owing to no voluntary act of his own. He was pressed forward by the throng, when, in the confusion of that midnight march, it became a matter of "every man for himself."

Rarely has history recorded an instance of such signal vengeance or a more disastrous retreat. If the Mexicans had followed up their advantage, or had stationed a force of warriors to intercept the Spaniards at Tacuba, not a single one could have escaped. That any did so was owing to their negligence; but they seemed satisfied with this venture in nocturnal warfare. Their desire for blood was for the moment glutted, and they desisted from following the retreating Spaniards, in order to sacrifice their prisoners, perhaps to plunder the wreckage, and bury their dead.

The causeway to Tacuba was not the most direct route for the retreating Spaniards to follow, having Tlascala as the objective of their journey; but it was the shortest. In order to reach Tlascala (which by common consent was now their goal), they were compelled to make a wide detour around the northern end of Lake Tezcoco, and the first night they fortified themselves in a temple on a hill nine miles distant from Mexico, where, many years later, a chapel was erected in remembrance of their woes. They halted here only long enough to sleep, to dress their many wounds, and make arrows for their cross-bows, the next day moving on, though slowly, under the guidance of a Tlascalan, who alone knew the way to their hoped-for haven of refuge. Their only food for several days consisted of the flesh of a horse, slain in the fight (and which they devoured even to its skin), a scant supply of green corn, and the roots of grasses, which the Indians dug out of the earth with their teeth.

In this manner, constantly assailed by hovering bands of Indians, the feeble remnant of that band of conquerors (who had defied Montezuma in his capital and made all Mexico ring with the fame of their achievements), struggled forward towards Tlascala, nearly 100 miles away. "God only knows," wrote Cortés, "the toil and fatigue with which this journey was accomplished; for of twenty-three horses that remained to us, there was not one that could move briskly, nor a horseman able to raise his arm, nor a foot-soldier unhurt!"

During a week of weary and painful marching, the war-worn heroes hobbled on, the wounded on crutches, the sick and dying borne on horseback, their ears ever assailed by the shouts of hostile savages, "Hurry along, robbers and murderers, hurry along; you will soon meet with the vengeance due to your crimes!" After passing through a gap in the mountain range which encloses the valley of Mexico, they beheld what the threats of the Indians had implied: a vast host, estimated at more than 100,000 warriors, gathered in battle array on the great plain of Otumba. It was within sight of the famous pyramids of the sun and moon, at Teotihuacan (ominously named the "City of the Dead"), that the Aztec army, so long in gathering, was massed for the final struggle; and when the Spaniards beheld the swarming legions, with waving plumes, and weapons glancing in the sun, they justly feared their end had come.

Amid those myriad foes they were, as a Spanish historian has truly said, "like an islet in the sea, attacked on every side by roaring breakers"; but, though despairing, they were undismayed. After a brief harangue, Cortés formed them in phalanx, the foot-soldiers in the centre, the horsemen on the flanks, and like a rock they withstood the shocks of these roaring seas; but soon crumbled away under the repeated attacks.

The odds were greatly against the Spaniards, for they had not only lost prestige by defeat, but they had lost all their cannon and arquebuses. It was a hand-to-hand fight, after the manner of most ancient times, and to the bitter death, in which the best men, and the most enduring, would certainly win. There seemed no doubt which way victory would go, for the Aztecs outnumbered their foes more than 100 to one. But the tide was turned by Cortés himself, who, in the thick of battle, chanced to espy the cacique in command, surrounded by his chiefs, beneath a standard blazoned with the royal arms and glittering with gold. Knowing the superstitious reverence with which the Aztecs regarded their leader and this banner, and realizing that only by a most desperate stroke could he avert total defeat, he shouted to Sandoval and others: "On, gentlemen, let us charge them. 'Santiago! Santiago!' The compact body of horsemen pierced the multitude of Aztecs like a wedge, dispersed the chiefs or trampled them down. With his own lance Cortés pinned the cacique to the ground, while one of his captains snatched the imperial banner and held it aloft for all to see. Instantly there was the wildest confusion in the ranks of the Aztecs, who, uttering howls of rage and despair, gave up the contest and fled the field.

It is to the honor of Cortés that he did not vaunt himself over the part he played in this affair, but, rather, wrote of it very modestly to his sovereign, "And we went fighting in that toilsome manner a great part of the day, until it pleased God that there was slain a person of the enemy who must have been the general, for with his death the battle ceased." That victory was the greatest the Spaniards had won, the slain having been put at 20,000; but they did not dare follow it up, and were only too glad to resume their march to Tlascala, which they reached three days later, or about July 10th.