Why is a shire horse called horse?

The word "shire" comes from the Old English word "scir", which means "county" or "region". Shire horses are large, draught horses that were originally bred in the English counties of Lincolnshire, Cambridgeshire, and Norfolk. They were used for pulling heavy loads, such as ploughs and carts. The name "shire horse" is therefore a reference to the region where these horses were bred.