The Waler is a scarce breed originating in Australia, where it was bred as a fine cavalry and stock horse during the era of the British Empire. Walers were highly regarded for their stamina, hardiness, agility, trainability and bravery in battle. By the 1940s the cavalry breeding program had been abandoned, and most remaining Walers were turned loose, becoming feral horses, while others went on to develop into the modern Australian Stock Horse. In the mid 1980s a move was made to round up surviving feral Walers, which were at risk of being shot or sent to slaughter as part of a government eradication program. The Waler Horse Society of Australia was formed at that time, and has been active in promoting this hardy, athletic breed as a sport horse.
The Waler has an interesting background, being strongly influenced by the Indonesian Timor Pony and the South African Cape Horse, with much additional mixture of European coach and trotting horse breeds, draft horses, Thoroughbred, and Arab. The original Waler was not bred according to fixed standards, but rather by type; today it continues to be quite variable in appearance. However, the new organization takes into account the current preference for purebred horses, and requires registration and breeding records to be kept.
Yarramalong Waler Stud has a wesbite full of photos showing historic and modern Walers in all sorts of activities. Also interesting is this page which quotes from dozens of historic sources, revealing the varied breeding programs and types of horse used by the military. They are affiliated with another association, the Waler Horse Owners & Breeders Association, which has broken away from the Society mentioned above, with somewhat different breeding guidelines and goals.