Despite the fact that humans have ridden and used horses in some capacity of another for thousands of years, we have only really discovered relatively recently exactly when it was that horses were first domesticated.

It is thanks to horses that we learnt to travel, to move goods around and event to fight in wars. There is an argument that they, rather than dogs, are actually a man’s best friend. What many might not realise is that we have worked with horses since 3,500 B.C.E. and that the animal was associated with human groups even before that date.

In other words, just because we will often think of working with horses in generally quite modern situations, the reality is that the relationship between man and horse is one that dates back almost as far as our history stretches.

As molecular archaeologist Ludovic Orlando says, “Humans are the animal that has changed history.” The breeds of horses that we know of in the modern world go into the hundreds, with evidence suggesting that the first horses were domesticated in the Eurasian Steppes, with evidence showing that the modern horse probably comes from Western Eurasia in 2,200 B.C.E.

Defining ‘Domestication’

If you want to have a solid answer about when it was that horses were domesticated, you first need to decide what it is that you mean when you talk of ‘domestication’. For some zoologists, domestication is defined as the human control over breeding. This can be detected in skeletal samples, for example.

For others, domestication can mean something slightly different. There are researchers that look at the likes of working activity and the lifestyle patterns of humans at various times when they are looking to decide whether an animal was domesticated or not at a particular time.

There has been an attempt to look at the likes of genetics and studying the physical remains of a horse in order to decide whether or not they were domesticated. The problem is, this depends on there having been a separation of the genotypes of wild horse populations compared to the domesticated horses.

A separation almost certainly took place, but when this was in terms of the exact split isn’t easy for researchers to pin-point. Whether you use the narrower zoological definition of domestication or the broader cultural one will depend on when you think the domestication took place.

Studying DNA

In order to get a sense of when horses were first truly domesticated, scientists followed in the footsteps of the 2010 study into Neanderthal DNA. The scientists were able to trace the manner in which wild horses shared their DNA across the Bering Strait, moving between Asia and North America.

It revealed the history of Przewalski’s horses, long thought of as the last wild horses on the planet. They then worked with modern samples and saw how management by people has seen something of a reversal of the diversity of horse genomes, albeit whilst adding breed-specific features.

Until late-2021, there wasn’t enough ancient DNA to be able to answer the question about domestication with any sense of accuracy. At that point, scientists reported analysis of more than 250 genomes from ancient horses, allowing them to fill that particular piece of the puzzle.

Looking at fossil bones and teeth, scientists managed to trace the origins of horses back about 50 million years, starting with a hoofed animal known as a Hyracotherium that was about the size of a dog. The genus of Equus, which is the horse as we know it, emerged around 4.5 million years ago.

Early Humans & Horses

The first humans, which wouldn’t have appeared for about another million years after the first members of the Equus line, would have seen horses around in much the same way that they would have seen other animals.

We know that there are horses depicted in cave paintings from the Stone Age, for example. Rather than look upon them as an animal to be tamed, however, they almost certainly would’ve been hunted as food. Other animals were domesticated first, with dogs coming into our lives about 15,000 years ago, before sheep pigs and cattle around four to seven thousand years after that.

The clear evidence around the domestication of horses didn’t come about until around 5,500 years ago. Remains of horses from across Eurasia presented scientists with lots of evidence for the first domestication event, such as a mummified horse in Siberia that was discovered in 2018 and dated back to around 4,600 years ago.

Yet it is the discovery of a settlement in Botai, modern-day Kazakhstan, that was most intriguing to the scientists that were carrying out the domestication research. As well as bones of horses, there was also evidence of a ‘yard’ type area where they may have been kept.

That was from 3,500 B.C.E., with some of the pottery shards having chemical traces of mares’ milk. Some of the horse’s teeth showed signs of ‘bit wear’, which offered a suggestion that they had been bridled. As you might imagine, though, there has been some debate around the extent to which the site provides definitive evidence of domestication. Whilst they may have kept horses close for meat and milk, even riding some, there isn’t evidence that the bred them or used them as a pack for transportation. That is why it is important to decide what you mean by ‘domestication’.

As a result of that definition, an annual review of genetics carried out in 2020 concluded that ‘the geographical origin of domestic horses is presently unknown.’ More than 150 collaborating scientists worked together in order to try to come up with an answer, but it essentially required them to engage in ‘a numbers game’.

By 2021 it was decided that ‘the homeland of modern domestic horses was the part of Western Eurasia between and north of the Black and Caspian seas’. The where makes it slightly easier to decide the when, but definitions may ultimately mean that we never know that for certain.