The NHL, one of the four major sports leagues in North America, was formed in 1917 and last year celebrated the 100th anniversary. We already know how it developed after the 1942, when the Original Six era has begun, and now it's time to take a look at the early years. A lot of changes, a lot of unfamiliar teams.
The NHL had a predecessor, the National Hockey Association (NHA) which was established in 1909 and all of the teams were Canadian. There were disagreements between owners which caused the five NHA team owners started the NHL to continue to play while the NHA operations were suspended to get rid of an unwanted owner (Eddie Livingstone, Toronto Blueshirts). A year later, in 1918, the NHA ceased to exist.
Montreal Canadiens, Toronto Arenas, Ottawa Senators and Montreal Wanderers played in the first NHL season. Quebec Bulldogs was a member of the League also but didn't play in the first season. However, only four games were played between the four teams, then the Montreal Wanderers arena burnt down and this team withdrew from the league.
The Quebec Bulldogs started to play in the NHL since the second League's season, so we can say it was the first expansion. On the other hand, Quebec already was a member of the NHL. Also, the Stanley Cup champion Toronto Arenas was renamed to the Toronto St.Patricks. A year later Bulldogs relocated to Hamilton and became the Hamilton Tigers. Four more seasons the structure of the NHL was the same until two new teams joined the League in 1924, Boston Bruins and Montreal Maroons. Bruins became the first American team in the League. Another two teams were added to the NHL the next year, Pittsburgh Pirates and New York Americans. The roster of the Americans was composed of the Hamilton Tigers players, whose contracts were purchased. The franchise from Hamilton left the NHL.
In 1926 the NHL reached the maximum number of the teams (10) before the Expansion era began in 1967. Chicago Black Hawks, Detroit Cougars, and New York Rangers joined the NHL, so all the Original Six teams already played in the 1926-27 season. The same year the Toronto St. Patricks changed its name to the Toronto Maple Leafs. After four years without changes, the Pittsburgh Pirates moved to Philadelphia, becoming the Philadelphia Quakers, and Detroit Cougars changed its name to the Detroit Falcons in 1930. The next name change took place two years later when the Falcons was renamed the Detroit Red Wings.
The NHL grew for 14 consecutive seasons, but before the 1931-32 season the number of the teams was reduced to eight: the Philadelphia Quakers and the original Ottawa Senators left the NHL. However, Senators rejoined the League after missing one season, played two more years in the capital of Canada and relocated, becoming the St. Louis Eagles in 1934. But this franchise from St.Louis played just one season in the NHL and folded.
The number of the teams reduced again in 1938 when the Montreal Maroons left the League. Just the Original Six teams and the New York Americans stayed, but not for a long time: in 1941 the Americans changed their name to the Brooklyn Americans, played one more season and left the NHL, too. The Original Six era has begun.
As we can see, the oldest NHL team is the Montreal Canadiens, which was founded earlier than the league, in 1909. They never changed their name, never changed their logo drastically and also Canadiens is the most titled club in the NHL - they won Stanley Cup 24 times, almost two times more than the Toronto Maple Leafs (13).
The original Ottawa Senators isn't a predecessor of the current Ottawa Senators. It's just a franchise of the same name in the same city established in 1990 (the first NHL season started in 1992).
Here's the video showing how the NHL's map changed through the years including all the teams' joining, leaving, relocating, renaming, logo changing.