The Doberman Pinscher was developed by a German tax collector named Louis Dobermann around 1900 to protect him when he was out collecting taxes in bandit-infested areas. Louis likely crossed the old shorthaired shepherds, german pnschers, Rottweielers, great danes, weimaraners, greyhounds, and terriers. Today the breed still serves as a protection and guard dog but also excels in dog sports and as a companion.
http://www.dogbreedinfo.com/doberman.htm
http://www.akc.org/breeds/doberman_pinscher/
http://en.wikipedia.org/wiki/Doberman_Pinscher#History