When Colonial Spanish horses were first imported to North America, horses were as ubiquitous and varied in type as cars in a modern parking lot. The recent leaps in equine genetic research has helped to increase our understanding of how those horses were perceived and bred as well as how they were built.
Queen Isabella was insistent that only ‘caballos del camino’ were exported to the New World. Garrons and Galiceanos, were the most common ‘caballos del camino’ imported to North America as work horses. They were used in harness, as pack animals and often slaughtered for meat as well.
Modern descendants of those ‘caballos de camino’ are often laterally gaited. Pacers are faster than trotters, so added speed to carriage horses. And a paso, or broken gait, offered a smooth rapid ride under saddle.
Research now informs us that Garrons and Galiceanos of Portugul and Spain are related to the lineages of the Celtic ponies, including the Scottish Highlander and the Fell ponies of the British Isles. The Celtic ponies show the open or obtuse angle at the hip and shoulder that enables them to excel at thrusting themselves forward to push against the breast collar when in harness. There may be some variation in the biomechanics of types selected for strength to haul a heavily loaded cart or for speed when harnessed to a carriage.
‘Caballos del campo’ have been more difficult to define. Horses imported for their speed by the Colonial Spanish were called Arabs. Research now informs us that while the horses so highly prized as flat racers were of Eastern origins, they were actually of Turkomen descent. Since Thoroughbred stallions carrying strong Turkomen traits were added to free-roaming herds after 1880, genetic markers that show Turkomen influence do not guarantee Colonial Spanish ancestry.
We do know that the aristocratic institutions of baroque horsemanship considered only Square and Rectangular horses worth schooling. The Baroque schools flat out refused to train harness horses with an open or obtuse angle of 100-120o at the hip and shoulder. Pacers were and are still looked down on in classical horsemanship.
However, the Rectangular horses of Baroque times showed a 90o angle at the hip and shoulder. They have a more level pelvis that harness horses. If you find a light-bodied long-limbed Colonial SPanish horse with a 30o angle at the pelvis AND right angles at the hip and shoulder, then you may have a horse descended from the original outstanding flat racers.
The Barb and Sorraia horses imported to North America included individuals that were phenotypically Square Horses. These are the horses that made Queen Isabella’s fears that mounting the indigenous peoples on ‘caballos del campo, on agile swift surefooted horses prized for soundness and endurance in rough terrain while working cattle or excelling in battles and raids well founded. Renowned as the mounts of that finest light horse cavalry, Square Horses have been prized for their soundness and endurance as well as their feats of agility whether those are revealed through High School movements, raiding and cavalry marches or by working cattle for millennia. These horses are the antecedents of the ideal Spanish Mustang, the mount that allowed the Horse tribes of the Great Plains to survive all efforts to exterminate them.
Recent research now informs us that the Colonial Spanish horses found in the harsh arid lands of the American Southwest carry genetics that place them at the earliest known branches of the Barb and Arab genetic trees. They are Square Horses with distinctive conformational features typical of animals that have evolved to thrive in high, dry and cold climates with rugged terrain. Horses that meet the physical criteria below may be noted as being of ideal “Square Horse’ phenotype.

Anatomical Traits
- The Square Horse is actually a bio-mechanical diamond whose 90o angles at the shoulder and hip joints form an equal-sided square. Built like the scale prized by cavalrymen and High School horseman alike, line drawn through the top and bottom points of the square will be vertical, allowing the rider to sit perfectly balanced.
- On a Square horse, you can draw a horizontal line across the body of the horse from the points of the diamond that can be extended from the point of the shoulder to the point of the buttock
- On a Square horse, you can draw a vertical line from the point of the hip through the stifle to the ground that is parallel to the vertical line dropped from the point of the buttock to the ground following the line of the hind cannon bones.
- Because their long shoulder blade has a 45o slope, these horses typically have narrow but deep chests with the ball of the shoulder joint placed in front of the first ribs. The front legs stand fairly close together with the sternum even with or in some cases behind the points of the shoulder.
- The neck is deep and full with well-defined withers because the attachment of the seratus cervicalis muscle on the inside of the long sloping shoulder blades gives it both the length and the leverage to reach down to attach to the cervical vertebra and ribs and so elevate the horse’s forehand
- The 45o slope of the Square Horses shoulder is reflected in the ideal 45o angle of the pastern and hoof. The hooves of the Square Horse are ‘boxy’ with substantial sole, large frog, dense hoof wall and sufficient heel to protect the inner structures of the foot.
- The long gaskin of the hind leg of Square Horse is balanced by and reflected in the obviously long forearm and short cannon of the front legs. Because the biomechanics of the Square Horse emphasize the support phase of the stride, a cross section of the cannon bones appears round as bone is laid down in response to the even loading
- The distinctive broad forehead and wide-set ears typical of Colonial Spanish horses result from the unique shape of the atlas vertebra first noted by the ‘Bone Lady’, Sharon May Davis. Their first vertebra (atlas) has wings that are broader and more lobed, allowing the vertical profile and erect neck emphasized in Baroque horse portraits and 16th century classical dressage manuals.
Conformation and ‘Type’
- Because pelvis slopes 45o from the point of the hip to the hip joint, the croup is rounded with the tail set low on the body
- The chest is deep from the side view, and usually accounts for about half of the height of the horse from the ground to the withers.
- Colonial Spanish horse heads have straight to convex profiles with small crescent shaped nostrils allowing air to be warmed and moistened in the large sinus cavities before entering the lungs.
- The muzzle is usually very fine, and from the side the upper lip is usually longer than the lower, although the teeth meet evenly