I enjoy riding horses in my free time. Do you?
Horses in the Middle Ages differed in size, build and breed from the modern horse
That is true! My uncle raises horses, specializing in Pony of America horses which are bred to stay small, and American Quarterhorses the "typical American" horse
evolution of the horse, a mammal of the family Equidae, occurred over a geologic time scale of 50 million years, 
What are some horse breeds you are familiar with?
 Arab horse ( , DMG "ḥiṣān ʿarabī") is a breed of horse that originated on the Arabian Peninsula
the Clydesdale is also known as the gentle giant
Horses are particular used for  use of horses for practical working purposes, transportation, recreational activities, artistic or cultural exercises and competitive sport.