An article in the NY Times suggests that violence in hockey originated with Montreal ethnic gangs in the late 19th century.
http://www.nytimes.com/2011/12/11/s..._r=2&scp=1&sq=hockey fighting montreal&st=cse
http://www.nytimes.com/2011/12/11/s..._r=2&scp=1&sq=hockey fighting montreal&st=cse