Medieval War Horses Were Smaller Than Modern-Day Ponies - IFLScience
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.”