The American Hockey League is a minor professional ice hockey league in the United States and Canada. The American Hockey League serves as the top developmental league for the National Hockey League. The league played its first season in 1936 as the International-American Hockey League, a "circuit of mutual convenience" formed when the Canadian-American Hockey League and the International Hockey League agreed to play an interlocking schedule. After two seasons, the leagues formally merged, and after the 1939–40 season, the league became known as the American Hockey League.