Although the First World War was not the cavalry war the British expected, large numbers of horses were used to pull artillery and losses were high.[21] Because the war caused a depletion in stock, in 1920 and 1921, the British society opened a special register for previously unregistered mares of Cleveland Bay type, including some already registered with the Yorkshire Coach Horse (a Cleveland/Thoroughbred cross) registry, after they had passed an inspection that certified them to be of proper breed type. The subsequent foals of these mares were eligible for registration into the main British Cleveland Bay stud book, and were also eligible to compete in competitions reserved for breed members.