According to the Cleveland Bay Horse Society, "The Cleveland Bay is England's oldest breed of horse with a history that goes beyond a time when records were kept. It is an incredibly versatile horse that can turn its hoof to all disciplines, a legacy of its need to adapt through the ages to the changing face of civilization. It is a horse with substance, activity, stamina, and a temperament that is unsurpassed by any other breed of horse."
The CLEVELAND BAY HORSE SOCIETY
The CBHS is the breed society for Cleveland Bay horses and maintains the only studbook of the breed. CBHS handles all particulars regarding the breed including registration, licensure of stallions, and maintain the breed standards.
CBHS has a great number of Cleveland Bay resources and history on their website. See here...