* Flemish Horses: These heavy draft horses from Belgium were a major influence, contributing size, strength, and pulling power.
* Native Scottish Horses: Smaller, more agile horses native to Scotland also played a role, adding hardiness and stamina.
* Black Cart Horses: These horses were used for hauling carts and were likely a cross between various breeds, including the Flemish.
The Clydesdale breed was developed over many generations, with careful selection and breeding to create a horse with the desired characteristics for farm work and hauling.