The Greater Swiss Mountain Dog is one of the four Sennenhunds, or Swiss Mountain Dogs, the other three being the Bernese, Appenzeller and Entlebucher. The word Senn is the term for Alpine herdsmen, so a Sennenhund is a 'dog of the Senn'. Traditionally the Greater Swiss Mountain Dog was a draught dog, helping craftsmen and farmers that were too poor to afford horses.
It is believed that the Greater Swiss Mountain Dog is descended from large Molossers brought to Switzerland either by the Romans or Phoenician traders. Serious breeding programs for the Swiss Mountain Dogs did not being until the late 1800s and they were not formerly separated into distinct breeds until 1908.