] Yes, a shire horse is a specific breed. Their history is very long in England. Julius Caesar commented on these great (large) horses as British war horses. He also commented on the giants of Flanders. King John brought 100 Belgians into England to interbreed with the shire horses. Henry VIII forbade exportation of any shire horse, even to Scotland. But in Scotland the Clydesdale was developed for draughting (pulling) work on the farms and on the public roads. Another large horse developed in England is the Suffolk Jump. Percherons are a French breed. If the English at one time very loosely called Belgians and Percherons one breed, they would not have done so since the last century when careful stud books had been established for all registered breeds.
There are five main draft breeds. There are Percherons, Belgians, Shires, Clydesdales, and Suffolks. Percherons were bred in France. Their original use was as a coach horse, but as they became larger, they were used for farm work as well. Belgians were bred in the Netherlands and Belgium. They were primarily used for farm work. The Shire was originally bred in England as a war horse. Since the breed is the largest of draft horses it is often used to increase the size of other draft horses. The Clydesdale was bred in Scotland. They were never really popular as farm animals do to their excessive feathering. They are, however, very desirable for big hitches like you see with Budweiser. They can be matched well and have excellent underpinning (leg movement). The Suffolk (or Suffolk Punch) was bred in England. The Suffolk is the smallest and most compact of all the draft horse breeds, which is why it is sometimes called Suffolk Punch.