What Caused So Many Cultures To Disappear In 1400 AD?

I’m an archaeologist— drought leads to a struggle for resources, which leads to warfare, which leads to disease and destruction of culture and abandonment of regional homelands.

Populations in Europe also declined 8% between 1250-1400AD. Ice core records suggest very large volcanic activity that may have continued for a long time causing widespread cold climatic conditions (LIA), crop failures, and disease. For a culture that was highly dependent on corn that could no longer be reliably grown the effect would have been devastating. This may have caused the breakdown of social order, tribal warfare, and abandonment of a way of life. 1250- when Atlantic pack ice began to grow, a cold period that was possibly triggered or enhanced by the massive eruption of the Samalas volcano in 1257[19] and the associated volcanic winter. 1275 to 1300- when the radiocarbon dating of plants shows that they were killed by glaciation 1300- when warm summers stopped being dependable in Northern Europe 1315- when rains and the Great Famine of 1315–1317 occurred This is the best explanation I have yet read for the global depopulation and complete abandonment of the great southwest civilizations.

I'm an Architect by profession and i have travelled extensively in that region and have studied the Architecture and i believe the Architecture tells the tale. Everything was defensively built. They built lookouts on the high places, and food storage was hidden. As the population grew and drought more severe, it became survival of the fittest. Until even the last ones standing saw the place as haunted and cursed.

There was Volcanic activity near Flagstaff that deposited ash and cinder that was feet deep over vast areas of land. This would have contaminated not only the landscape and water sources in that area but also water sources downstream and south of Flagstaff. Your map showing the areas depopulated (6:37) looks suspiciously like a volcanic plume. I am building a home near Flagstaff and every time I dig for drain pipe or foundation work I run into a layer of cement-like material around 3 ft. down that is 6"-12" thick. Definitely volcanic in origin.

For more than 450 years, Norse settlers from Scandinavia lived—sometimes even thrived—in southern Greenland. Then, they vanished. Their mysterious disappearance in the 14th century has been linked to everything from plummeting temperatures and poor land management to plague and pirate raids. Now, researchers have discovered an additional factor that might have helped seal the settlers’ fate: drought. Reason would say some world wide event happened during this time too.

I read a very compelling book, "1421. The Year China Discovered America." It was subsequently supplemented by unusual things found in the Americas by other archeologists that support the theory. It's possible their interactions with coastal people, who then traded inland, brought disease. This interaction could cause the die-off of large numbers of people. Just a thought and worth the read regardless. Great episode. Love it.

I'm not an archeologist, but I am studying to be one, and I do agree that the sudden vacating of the region was too large to simply be coincidence. Personally, I think it may have been a combination of factors. A natural disaster in one area leading to refugees seeking shelter - the sudden increase in population being an excellent vector for disease, leading to more depopulation and seeking shelter elsewhere. Natural resources start to get depleted, and conflict becoming more likely, until eventually everyone had left the region and their cultures absorbed into the surrounding regions. It's possible we may never know exactly what happened. But it is food for thought. Especially when compared to similar instances in other parts of the world. The Bronze Age collapse of the fertile crescent being one instance that we're starting to understand more, and which might have some similarity to what happened here in the US. Great Video, Andy! Thank you!

The Fremont and Moqui cultures further north in Utah also dimished or disappeared around the same time frame. So this mystery was more widespread than just Arizona. Also this was the same time frame the Aztec culture was begining to grow and rise so dramaticly, according to them and archeologists they came from the north. I've had the same questions as you for many years, and hoping someone can make a positive connection about this issue.

The Salado of the San Pedro river valley had definitely shifted to a defensive posture just prior to their disappearance - this is amply demonstrated in the strong fortification features found at their last few consolidated villages such as Leaverton Mesa, 111 Ranch and and High Mesa. "Migrants and Mounds - Classic Period Archeology of the Lower San Pedro" makes for an interesting read on this marked cultural shift just prior to their departure from the San Pedro.

Great information. My folks had property South of Stafford Arizona. It had remains of old culture. We found buckets of pottery sheds and axes on the place.

There's a channel called Navajo Traditional Teachings here on youtube, the presenter is a Navajo historian/elder named Wally Brown. He has several videos where he speaks about the traditional stories of the Navajo about the Anasazi, which he sharply distinguishes from the Ancestral Puebloans and other groups of the region. As he relates it, the Anasazi were an outsider group who arrived fairly suddenly and remained for only a relatively short period, being centered in Chaco Canyon. Supposedly they went out raiding, conquering, and enslaving the other peoples, and even conducted human sacrifices, but were ultimately punished with a great wind that toppled their cities and dried up their water sources. During and after their reign of terror, the ancestors of the Navajo and the other groups fled the area to hide in cliff dwellings. I can't fully speak to how closely these stories align with the archaeological record, but they certainly seem to fit the main theories for the depopulation, especially if a period of prolonged violence coincided with a major drought. I could imagine a group attempting to impose something like mesoamerican style social and religious customs on the area, i.e. large stone cities, conquest of neighboring groups, blood and sacrifice focused religious rites, etc. could've caused such a depopulation.

During my time in the Marine Corps, I befriended a Sergeant of Diné descent who shared an intriguing version of the Skin-Walker legend, passed down from his elders. According to his account, the Skin-Walkers were remnants of a previous population, cursed for betraying their own families and tribes. My sergeant, a well-read and educated individual, interpreted this to suggest that the Skin-Walkers were survivors of a brutal conflict marked by acts akin to war crimes. He speculated that although the Skin-Walkers continued their old ways upon the arrival of the Diné, they were too few to overpower them. Nevertheless, the unconventional warfare waged by the Skin-Walkers left a profound impact on the Diné, giving rise to the enduring legend. This interpretation, while speculative, does not conflict with established facts.

Thanks Andy, you obviously put a lot of work into this. Since Native Americans have such a strong oral history, I would be interested to hear what their stories are. Nice work.

I remember hearing Krakatoa exploded around 1500AD. It affected everyone worldwide.

So solado pottery just stops completely in 1400? That seems very strange because up until that point, when Pueblo groups move into a new area, their pottery shows up in the record.

The same thing happened in Georgia, Alabama, western North Carolina and Tennessee around 1375 AD. The Black Plague hit Trondheim, Norway in 1349 AD then quickly spread to the rest of Norway, Iceland and Greenland. The Scandinavians abandoned Greenland in 1350 AD.

Very informative Andy thanks. I've read some papers suggesting conflict was common in the area based on skeletal injuries

Cool video, thanks Andy. So the Basket weavers were the hunter gatherer cultures, the pottery/agriculture followed and built sustainable cities of casas grandes so to speak, and, they all ran away abandoned centuries of infrastructure at culturally significant locations. Hmmmm. It’s an amazing story. I’m Chiricahua Apache with an Opata greatgrand dad and this puts things together for me.

WHAT A TRULY AWESOME VIDEO!!! Thank you.

Great video Andy , three reasons I don't believe they disappeared because of warfare. 1)No tribe had the amount of people it would of took to March the length & breath of Arizona through rough, hot,desolate terrain and wipe out all the other tribes that they encountered 2) Consider logistics all the food ,water, weapons and equipment you would of had to carry by foot since there were no horses till the Spanish reintroduce d them in the 1500s. 3)What did an invading army have to gain? Most of these tribes were dirt poor and had nothing of value to warrant such destruction.4) Tribes were not dictated to by a Chief,look at plains tribes they went on war parties if they wanted to for horses and glory they never wiped out whole tribes . Perhaps a paleoclimatolgist who studies droughts in past history could shed some light on past climate changes at that time. M T Cassidy Professor Native American Studies. Keep up the Good work