Hernán Cortés lucked out

I'm not sure what role disease played in Hernán Cortés's conquest of the Aztecs. I'm sure it weakened Mexico's Indian nations--destabilized their political and social institutions. Even though diseases quickly began killing Indians, they still outnumbered the Europeans by some huge margin--perhaps thousands to one.

As I wrote in Was Native Defeat Inevitable?(Mexican Version), Cortés barely escaped with his life during the so-called Noche Triste:Upon his return in late June, Cortés realized the Mexica had elected a new Hueyi Tlatoani: Cuitláhuac. Shortly thereafter, the Mexica besieged the palace housing the Spaniards and Moctezuma. Cortés ordered Moctezuma to speak to his people from a palace balcony and persuade them to let the Spanish return to the coast in peace. Moctezuma was jeered and stones and darts were thrown at him. He fell with what was reported as a concussion. Moctezuma died a few days later; whether from his injuries or murdered by the Spaniards, it is not known.

Under attack, with food and water in short supply, Cortés decided to break out of the city. Bridges on four of the eight causeways into the island city had been removed, so a portable bridge was devised. The gold and other booty stolen from the Mexica was packed; many of the Spaniards had looted as much gold as they could carry. Horses' hooves were muffled.

On the night of June 30, 1520, his large army left their compound and headed west, toward the Tlacopan causeway. The causeway was apparently unguarded, and the Spaniards made their way out of their complex unnoticed, winding their way through the sleeping city. Before reaching the causeway, they were noticed by Mexica warriors, who sounded the alarm.

The fighting was ferocious. As the Spaniards and allies reached the causeway, hundreds of canoes appeared in the waters alongside to harry the troops. The Spaniards and their native allies fought their way across the causeway in the rain, sometimes using the portable bridge to cover the gaps, although as the battle progressed some gaps had become so filled with wreckage and bodies that the fugitives were able to walk across. In some cases, the gold and equipment weighted down the conquistadores so much that they drowned.

But a recent article notes the role of disease on this particular occasion:

A germ of an idea

Thirty-four years ago, William H. McNeill, AB’38, AM’39, shed new light on world history—by giving microbes their proper place in the human drama.

By Robert Goodier"I read the story of Cortéz and couldn't believe it," McNeill says. The conventional story of how Tenochtitlan [modern-day Mexico City] fell to Hernán Cortéz and a small band of Spaniards in 1521 seemed to contradict common sense. At one point, the Aztecs had beaten the Spaniards back but did not press their advantage. "A considerable number of the Spanish were wounded in the retreat but there was no follow-up," McNeill says. "I couldn't figure out why the nephew of Montezuma, who organized the attack, didn't surround the Spaniards and bring them up to the top of that temple and cut their hearts out the next day. It's what should have happened."

And yet, it didn't. Instead, the Spaniards conquered Mexico and converted millions of Aztecs to Christianity. "I was sort of mulling this over in my head," McNeill recalls, "and somebody casually remarked that smallpox had broken out in Mexico City the night of the noche triste"—the night of the Spaniards' retreat—"and Montezuma's nephew died of it that same night."Comment:  I'm not sure what this dead nephew refers to. Wikipedia reports the following:

Moctezuma IIMoctezuma was then succeeded by his brother Cuitláhuac, who died shortly after during a smallpox epidemic. He was succeeded by his adolescent nephew, Cuauhtémoc.CuitláhuacAfter having ruled for just 80 days, Cuitlahuac died of smallpox that had been introduced to the New World by the Europeans.Since nephew Cuauhtémoc ruled until the empire fell, I don't know which nephew died on La Noche Triste. Wikipedia doesn't refer to any other nephew. But I think Moctezuma had many nephews, so I presume one was in position to take charge that night.

Cortés lucked out when no arrow hit him during his escape. He also lucked out when smallpox broke out in Tenochtitlan that night. Not only did it kill Moctezuma's nephew, it undoubtedly wreaked havoc. The one time the Aztecs needed calm and order, they probably faced a panic-inducing crisis instead.

Once Cortés escaped, he rested beyond the city. If the Aztecs had pursued him, they could've had him. But it seems they didn't have the necessary manpower or leadership. People were too busy dying to worry about Cortés.

Conclusion

We're talking about a turning point in world history here. If there hadn't been a smallpox outbreak that day, Cortés probably would've died. If the Cortés expedition had failed, the conquest of Mexico might've been postponed indefinitely. The epidemic hit Tenochtitlan on literally the worst possible day.

Thus we see how capricious history is. A small change here or there could've led to a markedly different outcome. The Aztec empire might've fallen anyway, but some Native nations could've survived as small independent states. Tribes in the US and Canada remained independent a century or two after first contact, and that could've happened in Mexico too.

For more on the subject, see Was Native Defeat Inevitable?