Rome, until after the conquest of Gaul, was deemed a weak nation in some respects, and when we study the history of Rome at about that period we find the weakness to have been in a measure attributable to Rome's shortage of horses during the greater part of that long spell.
Coming to what has been termed the Arabian period, history proves beyond all doubt that the spread of Islam was due partly to the Arabians having at about that time become possessors of many horses.
Indeed had the Franks not owned a great number of exceptionally fine horses by about the beginning of the sixth century A.D., who can say that the Saracens would not, after the year 732 A.D., have vanquished the larger portion of Western Europe?
Again, what chance of victory would the Normans have had at Hastings had Harold's forces been mounted on horseback? For when we remember the valiant way that Harold and his men fought it is easy to believe that the Normans would have been completely routed had they too been fighting on foot and not on horseback, in which case the entire history of this country would very likely have been different.
In the Middle Ages we find the horse playing if possible a more important part in the making of history than it had done in the previous centuries, for what would have become of England's power, and her prestige, had she been deprived of those great war horses and the almost invulnerable men-at-arms who bestrode them?
England's might spread steadily while the strength and size of her horses went on increasing, and while the weight of the armour worn by horses and men grew gradually heavier and heavier.
The limit in weight of armour would appear to have been reached when a horse became compelled to carry a man and armour that weighed together between thirty and three and thirty stone.