Justin, Friesian Horse Who Paints

Ancestors of the modern Friesians were used in medieval times to carry knights to battle. In the 12th and 13th centuries, some eastern horses of crusaders were mated with Friesian stock. During the 16th and 17th centuries, when the Netherlands were shortly linked with Spain, there was less demand for heavy war horses, as battle arms changed and Andalusian blood was added, lightening their weights and thereby rendering them more suitable (in terms of less food intake and waste output) for work as more urban carriage horses.
The historian Ann Hyland wrote of the Friesian breed:
The Emperor Charles (reigned 1516 -56) continued Spanish expansion into the Netherlands, which had its Frisian warhorse, noted by Vegetius and used on the continent and in Britain in Roman times. Like the Andalusian, the Frisian bred true to type. Even with infusions of Spanish blood during the sixteenth century, it retained its indigenous characteristics, taking the best from both breeds. The Frisian is mentioned in 16th and 17th century works... a courageous horse eminently suitable for war, lacking the volatility of some breeds or the phlegm of very heavy ones. Generally black, the Frisian was around 15hh with strong, cobby conformation, but with a deal more elegance and quality. The noted gait was a smooth trot coming from powerful quarters. Nowadays, though breed definition is retained, the size has markedly increased, as has that of most breeds due to improved rearing and dietary methods.
The breed was especially popular in the 18th and 19th centuries, when they were not only in demand as harness horses and for agricultural work, but also for the trotting races then so popular. The Friesian may have been used as foundation stock for breeds such as the Dole Gudbrandsdal, the Norfolk Trotter (ancestor of the Hackney), and the Morgan. In the 1800s, the Friesian was bred to be lighter and faster for trotting, but this led to what some owners and breeders regarded as inferior stock, so a movement to return to pureblood stock took place by the end of the century.