When you picture medieval warfare, there's a good chance you imagine a horde of knights riding massive war horses into battle. Well, you're going to have to make a few size adjustments, because a new study has found that most war horses were no bigger than modern-day ponies. 

A team of archaeologists and historians from the University of Exeter analyzed the largest set of English horse bones from 300 to 1650 CE. Horse size was measured in "hands", an old unit equivalent to 10.16 centimeters (4 inches). Rather than the large horses of 17 to 18 hands high, they found that horses were often under the height of 14.2 hands. Modern-day ponies can range from about 14 hands to nearly 14.3 hands tall.

Publishing in the International Journal of Osteoarchaeology, the researchers say that when breeding war-horses, selection likely focused on other factors important to medieval warfare. 

"Selection and breeding practices in the Royal studs may have focused as much on temperament and the correct physical characteristics for warfare as they did on raw size," Professor Alan Outram, from the University of Exeter, said in a press release seen by IFLScience.

Even when a royal stud network was in place in the 13th and 14th centuries, horses that were 15-16 hands tall were rare – though people at the time would have seen them as incredibly large animals.

The tallest horse from the Norman period (1066 – 1075) researchers found was discovered at Trowbridge Castle, at around 15 hands. During the high medieval period, taller horses emerged, with some reaching 16 hands.

“Neither size, nor limb bone robusticity alone, are enough to confidently identify warhorses in the archaeological record," Researcher Helene Benkert, from the University of Exeter explained.

"Historic records don’t give the specific criteria which defined a warhorse; it is much more likely that throughout the medieval period, at different times, different conformations of horses were desirable in response to changing battlefield tactics and cultural preferences.”

It wasn't until the post-medieval period (1500-1650 CE) that the average height of horses became significantly taller, approaching that of modern-day working horses. So if you're picturing early English warfare, you might want to imagine something far closer to a modern-day pony ride – with a lot more brutal life-ending swordplay, of course.