[4][1][3] As the Belgian Shepherd had for centuries been bred for working ability with little consideration given to form, Reul found the type to vary greatly in appearance.
[1][5] As a part of their work, Reul's team assembled 117 specimens and began the process of standardising them into distinct varieties.
[6][2] In 1956 the current breed standard was adopted and it specified the four varieties known today; the Groenendael, Laekenois, Malinois and Tervuren.
[1][2] Rose owned a long-haired, black Belgian Shepherd bitch called "Petite", liking her look so much he spent over a year searching for a suitable mate, eventually finding a dog named "Piccard D'Uccle" who belonged to a shepherd called Mr Beernaert.
[7] During the First World War, Groenendaels were used by the Belgian Army to locate wounded soldiers and carry messages.
[6][5] The variety takes its name from the Mechelen region (called Malines in French), where it was the predominant coat type used by the local shepherds.
[6][1][5] The Laekenois variety has always been the rarest; they take their name from the Château de Laeken, a residence of the Belgian royal family.
[6][2] The Laekenois was a favourite of Queen Marie Henriette, who frequently watched them in the service of the shepherds who grazed the royal domains around the château; this patronage contributed to their popularity at the time.
[4][6][1] Most of the world's national kennel clubs including the Société Royale Saint-Hubert, as well as the Fédération Cynologique Internationale, recognise the Belgian Shepherd as a single breed with four distinct varieties.
[8][5] The American Kennel Club recognises the four varieties as separate breeds, leading to some difficulties for American breeders who breed from imported European stock: European Groenendaels in particular can whelp Tervuren-coloured pups; in most of the world these can be registered as Tervurens, whereas in the United States they would be disqualified from registration.
[6][1][9] According to the breed standard a dog that stands 62 centimetres at the withers should have a head 25 cm (9.8 in) long and a muzzle approximately half that length.
[8] The Malinois variety is short-haired, it is fawn in colour with black overlay, with a charcoal-coloured face and extremities.
While Belgian Shepherds of all coat types require ample exercise, the breed adapts well to living indoors.
[6][1] In recent times, the Laekenois has been employed by the Belgian Army in a variety of roles (in addition to the longstanding use of the Malinois), and the Tervuren is frequently used by government organisations as a drug detection dog.