Perhaps one of the oldest breeds of dogs in the world, the pug originated before 400 BC as a companion lap dog. It is most commonly believed that the pug came from Asia. However the oldest known records come from China where they were used as companion dogs in Buddhist monestaries in Tibet. There are also records of the breed in Japan and Europe around the 16th century. The breed was brought to America in the 19th century and recognized by the AKC in 1885. It is likely that the pug is the ancestor of the modern day Pekingese and King Charles Spaniel. Today the pug is still a popular family pet and makes a good watch dog.
http://www.akc.org/breeds/pug/
http://en.wikipedia.org/wiki/Pug
http://www.dogbreedinfo.com/pug.htm