Professional hockey is currently associated with today's National Hockey League, with many people believing it was the first league of professional hockey. This is a far cry from the truth. The history of the various professional leagues, especially in the early 1900's, shows how what we today call the NHL spread from many roots.

professional hockey leagues

Following thedevelopment of the early professional hockey leagues from 1904 to the end of the 1920's is a great look at the sport of hockey as we know it today. A variety of rules were in place including the number of players on the ice, goaltenders not being allowed off their skates and the development of the bluelines and redlines high-lited this era of hockey.
The National Hockey League had been the only major professional league for a number of years when the WHA started up. Eventually folding with some teams merging into the NHL it changed the landscape of professional hockey.