The German Shepherd dog breed became commonly known as Alsatians after the Second World War, but are exactly the same breed of dog. They originated as a sheep dog (as the name implies), and are now used in a number of roles due to their high intelligence and trainability. They are exceptionally loyal and loving, but need to be trained well when they are a puppy.
The breed was created by Captain Max von Stephanitz, who primarily bred the dogs as working dogs. They are highly intelligent and can be trained to do a number of tasks. Some of the more well-known roles of the breed include working as police dogs and guard dogs.
The breed is predisposed to a number of medical conditions such as hip dysplasia and elbow dysplasia, so I would really recommend looking into the medical history of both parents and preferably even grandparents (conditions such as hip dysplasia often do not become apparent until middle age) before buying one of these dogs.
The average lifespan is around 9 years, but they can live for up to 12 years with the right diet, genetics and lifestyle.
They usually grow to about 55-70 cm in height and weigh between 25 and 40 kgs in peak condition.