People in a vast swathe of the Eurasian continent, from Britain in the west to Bengal in the east, are speakers of languages that belong to the same linguistic group—the Indo-European family. About half of the planet’s population today speaks an Indo-European language.
This is a remarkable fact: It means that around three billion people speak tongues that descended from what was, once upon a time, a single language and was spoken by a group of nomads whose numbers wouldn’t have been larger than that of a tribal confederation.
How did this single language, which linguists have taken to calling Proto-Indo-European, spread across the word, giving rise to entities as diverse as Sanskrit, Greek, Latin, French, Persian and Bhojpuri?
The nomadic tribes that spoke the language spread through large parts of the known world around 6,000 years ago. In the words of anthropologist David W. Anthony, writing in his fantastic book on the spread of the Indo-Europeans, The Horse, the Wheel, and Language: How Bronze-Age Riders from the Eurasian Steppes Shaped the Modern World:
The people who spoke the Proto-Indo-European language lived at a critical time in a strategic place. They were positioned to benefit from innovations in transport, most important of these being the beginning of horseback riding and the invention of wheeled vehicles.
Horses, wagons and chariots gave these Indo-Europeans certain advantages militarily over the existing settled societies of Europe and Asia. Another innovation was biological: Indo-Europeans developed a gene mutation that allowed them to digest milk even after being weaned, thus providing these nomads with a continuous and mobile source of nutrition. We can see echoes of these historical facts in the culture of the early Vedic people who venerated horses and frowned upon the killing of milch cattle.
Where was the Indo-European homeland?
While this much the experts agree on, there are two competing hypotheses for the place of origin of these Indo-Europeans (or, as they were earlier known, the Aryans). The conventional view places their homeland in the Pontic steppe, which corresponds to modern-day Russia, Ukraine and Kazakhstan. An alternative hypothesis claims that the Proto-Indo-Europeans spread from Anatolia in modern-day Turkey.
The latter hypothesis was recently backed up by a seminal study led by evolutionary biologist Quentin Atkinson from the University of Auckland in New Zealand, which was published in the journal Science. Here is an animated map that illustrates the results of that research.
Politics behind the theory
For a dry thesis on human prehistory, the Indo-European theory of migration has caused enormous upheavals in the modern world. Because these initial Indo-European speakers had been able to get about and, in many cases, managed to spread their culture around, a certain Mr Hitler, who considered himself a descendant of these people—the Aryans—mangled the theory into one of racial supremacy.
Race as a concept is mostly nonsense but the damage that Hitler caused with it meant that academics stopped using the word “Aryan” lest anyone think they were talking of a blue-eyed, blonde-haired alpha people (although Indian text books are yet to get the memo). “Indo-European” is the correct term now.
While the Nazis had gone overboard in their acceptance of Aryan migration, at the other end of the spectrum, many of the very people who had coined the word “Aryan” have rejected it completely.
The Hindutva out-of-India myth
In India, driven by the 20th-century ideology of Hindutva, which made nationality a matter of historical association with the subcontinent, a few people vehemently dismissed this now-standard academic consensus of migrants from the north-west bringing into India key cultural markers such as the nascent Vedic religion and early forms of Sanskrit, the liturgical language of modern Hinduism.
Instead, hemmed in by doctrine, Hindutva ideologues such as Belgian Indologist Koenraad Elst try and explain the massive spread of Indo-European languages by postulating that the original home of these Aryans was India—a theory almost as ridiculous today as intelligent design or a flat earth hypothesis.
With the Hindutva ideology gaining popularity, you now have a huge number of people who consider this sort of dodgy stuff to be authentic. And as we can see from peeping across our western border, believing in a wonky, made-up history can have terrible consequences.