Did the Aryan Invasion Destroy the Indus Valley Civilization?

2000 - 1500 BC, India/Pakistan

“The Aryans destroyed the Indus Valley Civilization!” Jay’s uncle Wray declared during in the heated Facebook thread. “And the truth will come out soon!”

But did they really? What evidence do we have? And before we get into all that, here’s a little background so this all makes sense.

The Indus Valley Civilization (IVC), also known as the Harappan Civilization (or Sindhu-Saravasati, as some have begun to call it, referring to the Sanskrit Vedic era names of the two major rivers of the period), flourished from around 3500 to 1900 BC in what is today Pakistan and northwest India. It was one of the world’s earliest urban cultures, known for its advanced architecture, urban planning, water management, and sophisticated sewage systems. Major cities included Harappa and Mohenjo-Daro in today’s Pakistan and Rakhigarhi, Dholavira, and Lothal in India. The IVC existed alongside the major civilizations of the time, namely Egypt, Minoan, and Mesopotamia (Sumerians, Assyrians, Akkadians). The IVC thrived along great rivers such as the Indus and the Saraswati, a now-extinct river mentioned in ancient Indian texts, but its course is not fully resolved.

The story goes that something happened around 1500 BC, give or take a couple of hundred years. The IVC cities were abandoned, and supposedly, a new people began flourishing.

The Aryans.

Those Darned Aryans

It seems that the Aryans, a people from what is today Iran (the word Iran possibly evolved from Aryan), violently attacked the peaceful IVC society and wiped them out. This theory held for a long time, but it doesn’t hold much water anymore.

So let’s look deeper into it. If this assertion is true, we need to find some evidence of this invasion, right? It’s called testing a hypothesis. You either find evidence to prove or disprove the hypothesis. Like, say, some literature that speaks of these Aryan-IVC wars. Or maybe stone inscriptions that discuss these invasions. Perhaps archaeological evidence of burned cities (yes, we’ll talk about how this is a popular method to figure out destruction), massive graveyards, skeletons with battle injuries, or the existence of later “Aryan cities” built on those they occupied or destroyed. One or more of these have to be true for us to say with some certainty that this was an invasion.

But even before we get into that, we have to piece together a picture of who the Aryans were at the time of this supposed large-scale invasion or migration.

Our best records of the earliest Aryans come from the Vedas. These are ancient Indian texts that are still widely recognized, and whose hymns are practiced. The oldest of them is the Rig Veda, dated to around 1500 BC. These oral hymns were constructed in Sanskrit, an Indo-European language. Research suggests it has a “European” element because of similarities between Sanskrit and, say, Latin. Don’t believe it?

1. éka ūnus
2. dvá duo
3. trí trēs
4. catúr quattuor
5. pañca quīnque
6. ṣaṣ sex
7. saptá septem
8. aṣṭá octō
9. nava novem
10. dáśa decem

Pretty cool. There’s a lot more where that came from. Like Daivos for divinity, which is Deva in Sanskrit.

We also know from records that, for example, the ancient Mitanni, who lived around 1300 BC, were ruled by a class of people whose deities were the same as Vedic gods, such as Indra and Varuna. They worshipped “Ashwa,” which meant horse (in Sanskrit). Where did the Mitanni live? They lived in what is today modern Syria. These research elements suggest that at some point in history, a branch of people from some region migrated, carrying their early loanwords.

Such a branch, when it spread east, would have eventually reached the fertile Indus Valley, and they might have thought, “OMG! So much food and water! Attack!!”

Wait.

Not quite.

What evidence do we have for a powerful army marching down that route? I say “powerful army” because the IVC was not a small, insignificant group of people. At its peak, nearly a million people lived along the river systems, making it one of the largest civilizations of the time. Surely they weren’t all sitting around waiting to get butchered by a bunch of nomads? We have found no sign of continuous military fortifications along any routes from Iran to India dating to that period. Or cities. Or carvings. Nothing that suggests a large, structured attacking organization. How did a small bandit group end up destroying possibly hundreds of well-built cities and ending the IVC?

There have been plenty of debates about what happened. Recent scholarly research suggests something more mundane behind the decline of the IVC, something that has happened a lot and still continues to happen, though we have better ways to manage it.

Rivers changed course and dried up.

Regional climates changed.

As populations grew, internal strife and disorganization forced people to leave in search of better pastures.

These factors are not exciting to read, but they are more likely explanations. Studies show that the Ghaggar-Hakra River system (likely associated with the Sarasvati River) began to dry up around the 2000–1500 BC period, affecting agricultural productivity and leading to urban decay.

Put yourself in their world 4,000 years ago. You are heavily dependent on the nearby river and local agriculture. There is limited inter-city trade, at least not enough to sustain large populations. You’ve been hit with multiple droughts — and the impact doesn’t take centuries; it can occur in just a couple of years. The river that was a few hundred meters from the town is getting further away, and worse, is drying up. Your crops are dying, and your cattle are suffering.

At some point, you realize you can’t stay here and starve to death. So what do you do? Like most populations, you pack up and leave.

Why is this scenario more plausible? Let’s look at the evidence for violence. The remains of the cities do not show widespread signs of warfare or sudden destruction. Instead, the transition appears more gradual, with some regions demonstrating continuity in habitation.

A popular signature of ancient conquests is burned cities and mass graves. We see none of that here. IVC sites — including Mohenjo-Daro and Rakhigarhi — show no mass graves suggesting provable violence. We do have some ancient artifacts with arrows and other assorted weapons, but these could be for hunting and managing local conflicts, without suggesting a large-scale armed presence.

By and large, it appears the IVC was a well-run, peaceful agricultural society that decided agriculture wasn’t quite working where they were.

The prevailing theory is that the IVC declined even before the supposed Aryan populations arrived in their region. It’s quite possible that the first arrivals, wherever they came from, found already abandoned towns of a long-gone civilization (it gets more complicated, but just keep reading).

Another interesting thought is this: if the first Aryan groups saw many abandoned towns and villages, that might explain why they didn’t really build on top of them. They may have realized, “Oh, this isn’t a good place to settle,” and they too moved further east. Case in point: neither Mohenjo-Daro nor Harappa, two of the largest IVC settlements, show signs of re-habitation. People left those cities, and the cities vanished until they were rediscovered in the 19th century. It seems a little odd that an “invading” group simply left two prized towns alone.

What about literary sources?

Maybe somebody wrote something? Hang on. We’re talking about a time four thousand years ago. There wasn’t much writing going on then. Most traditions were oral, but that’s not to say there was no writing. By this time, the Egyptians were doing plenty of hieroglyphics, and the Sumerians and Akkadians were using cuneiform. In fact, by the 14th century BC, cuneiform had become the de facto script for correspondence among kingdoms in Egypt and Mesopotamia.

But compared to all the knowledge produced, the percentage represented by writing was still exceedingly limited — mostly a small, usually privileged group. The vast majority of the population was illiterate. While archaeologists have found thousands of instances of IVC symbols, they haven’t deciphered them. We don’t know if the symbols just stood for discrete “things” or if they were part of a more complex language.

And thus, we have nothing as yet from IVC sources that tell us anything about them. We don’t even know what they called themselves. Along with the Minoan Linear A script, IVC script remains a tantalizing challenge.

What about the Vedic texts? There is nothing in the Rig Veda (~1500 BC) that alludes to an invasion or war against any new native population. The references to wars in the Rig Veda typically pertain to people who were already Vedic in nature or tribes whose provenance is uncertain. Most of the Rig Veda, composed of over one thousand hymns, concerns itself with ways of life — philosophy, religion, cosmology, theology, rituals, ethics — and prayers.

The places and names in the Rig Veda indicate familiarity with the rivers around the Indus and further east (they called it the Sapta Sindhu — the land of Seven Rivers). The Rig Veda mentions long lines of seemingly Vedic kings, which suggests the Vedic Indians may have existed for centuries before the text was composed. If so, then the IVC should have been destroyed long before we think it should have been due to an invasion — but it hadn’t. So, does that mean they were already intermingling? Or could they all have been the same people who branched off earlier, some of whom left India long ago and returned?

In the ancient world, glorifying conquests was a big deal. Yet the Rig Veda simply talks of a long lineage of kings who all appear to be establishing and thriving for centuries by 1500 BC — but nothing about coming from some place and displacing the local population.

Genetic analysis

But there’s more. And it gets even muddier.

In 2019, a team of Harvard scientists and Indian archaeologists conducted a DNA analysis on a female skeleton in Rakhigarhi, one of the largest IVC settlements ever found. It is exceedingly difficult to obtain usable DNA from ancient samples in India due to the heat and humidity. From the sixty-one skeletal remains in a grave, they could only extract a viable sample from a single female skeleton.

This woman, from a farming community, walked this area around 4,500 years ago — around the time of the pyramids and about a thousand years before the supposed Aryan invasion. She belonged purely to the IVC. What was really interesting is that her DNA contained elements of proto-Iranian farmers who lived over 9,000 years ago. This suggests that the Iranian pastoralists didn’t need to introduce agriculture to India in the post-IVC world.

Could it be that there was an outward migration from India to Iran and other regions? That the original Aryan population actually came out of India?! That’s a whole new argument for passionate folks to get into a slinging match about.

Anyway, returning to the topic of the “invasion,” neither physical nor literary evidence suggests one. Given how scant the information is, could it still have happened? Of course, anything could have happened, but it seems very unlikely.

So, what might have happened?

There are three broad schools of thought.

Limited Intersection: In this line of reasoning, the Aryan migration simply followed the IVC’s decline. The people of the IVC had already migrated away from the valley, moving further inward into India and leaving behind their towns and cities. When the so-called Aryan people began to arrive, they had nothing to invade. Eventually, their actions converge with the next theory, one of assimilation.

Cultural Assimilation: Some scholars propose that the Aryan migration was more of a gradual assimilation rather than a destructive invasion. The incoming Indo-European-speaking people may have integrated with the existing populations, leading to a blend of cultures rather than a replacement.

Let’s slide into that ancient world for a moment. You’re standing on the rampart of your town’s little wall. Some folks are on the road — they don’t look too threatening. They come near with some cool-looking stuff they want to trade. They seem friendly. They say, “Namaste,” and you say something in return. Soon, the chief has them in your town, and they’re teaching you things while you’re teaching them things. Before you know it, they’ve become part of your family — worshipping your gods, but also rocking some sweet hymns. Your children worship both. Soon, there’s no “them” and “you.”

Over centuries, a new culture emerges — a mix of Vedic and IVC influence. This theory is now generally accepted as what might have happened. The key point: it wasn’t an invasion.

Continuity: There’s also another thought—that the Vedic Indians simply evolved from the IVC, as I covered in the DNA analysis section. This is the continuity hypothesis. In this line, the IVC people moved outward towards Iran, but we don’t have enough evidence yet to prove or disprove this. However, if we look at the timing of the Vedas and how they cover kings, it seems plausible that some Vedic kingdoms started east of the Indus and moved west. It is also plausible that a branch of the IVC moved east and evolved into a new tribe that became the Vedic Indians. But let me reiterate—all these are “what ifs,” and until they’re contested vigorously, they’re at best theories. Having said that, they’re all intriguing possibilities because we don’t have compelling evidence to counter them either.

In the end, while we can’t with great certainty prove the specifics of the Aryan migration one way or the other, available evidence suggests that the IVC declined due to environmental factors and that people moved away from their cities before the Aryans arrived, from wherever they came.

Whatever it was, it probably wasn’t an “invasion.”

To buy this in book format: here | For sources and acknowledgments see here.