As the name, Belgian Sheepdogs originated in Belgium....
They actually started as four varieties: the Malinois, Tervuren, Laekenois, and the Belgian Sheepdog (or Groenendael). The American Kennel Club recognizes all but the Laekenois as separate breeds, while in Belgium, all four are considered part of the same breed.
The black-coated Belgian Sheepdog was developed by breeder Nicolas Rose in the late 1800s, whose kennel dates to 1893. The European name Groenendael comes from the name of Roses estate outside Brussels, Chateau Groenendael.
During World War I, Belgian Sheepdogs carried messages and pulled ambulance and machine gun carts. Their popularity in the United States increased after the war, and the Belgian Sheepdog Club of America formed in 1919. Their numbers in the US decreased during the Great Depression, but they were again called into service during World War II, and interest has been on the rise ever since. They are currently ranked 125 of 175 breeds in popularity by the American Kennel Club.