The proper English name for the breed is German Shepherd Dog but they are usually informally referred to as GSDs or simply German Shepherds, although Alsatian also is commonly used in the UK (the reason for the alternative name is historical: during World Wars 1 and 2 Germany was out of favor in the UK and many names were de-Germanized).
The breed was originated by Captain Max von Stephanitz in the late 1800s and early 1900s. His goal was to breed an all-purpose working dog. Capt. von Stephanitz admired the landrace herding dogs of his native Germany, and believed they had the potential to be all-purpose working dogs. Additionally, he was aware of the declining need for herding dogs and believed that the breed would not survive unless it was put to other uses.
Well-bred GSDs have powerful jaws and strong teeth, can develop a strong sense of loyalty and obedience, and can be trained to attack and release on command. Poorly bred GSDs such as those from puppy mills can be fearful, overly aggressive, or both.
There are several types or lines of GSD and the behavior and conformation of each is quite different. The major lines are the international working dog, the international show dog, and the North American show dog. The working dogs are very high energy--they must be trained to do a job of some sort--and their appearance is somewhat varied. The international show dogs have less energy and a very consistent type or appearance. The North American show dogs have a markedly different type from the international dogs. Proponents of each style believe that their dogs represent the true German Shepherd Dog.
GSDs often compete and excel in obedience and schutzhund competitions.
They have a lifespan of about 12 years.