The Australian Cattle Dog (ACD or Cattle Dog), is a breed of herding dog originally developed in Australia for driving cattle over long distances across rough terrain. In the 19th century, New South Wales cattle farmer Thomas Hall crossed the dogs used by drovers in his parents' home county, Northumberland, with dingoes he had tamed. The resulting dogs were known as Halls Heelers. After Hall's death in 1870, the dogs became available beyond the Hall family and their associates, and were subsequently developed into two modern breeds, the Australian Cattle Dog and the Australian Stumpy Tail Cattle Dog. Robert Kaleski was influential in the Cattle Dog's early development, and wrote the first standard for the breed. The Australian Cattle Dog is a medium-sized, short-coated dog that occurs in two main colour forms. It has either brown or black hair distributed fairly evenly through a white coat, which gives the appearance of a "red" or "blue" dog.