Founded in Canada in 1978 by Michael MacMillan, Atlantis Films Limited later expanded its operations internationally. The Australian head office was located in Sydney. The company name was changed to Atlantis Communications Inc. in the mid-1990s and in 1998 merged with Alliance Communications Corporation to become Alliance Atlantis Communications Inc. Under MacMillan's leadership, the new company further expanded its sphere of business to include 13 Canadian specialty television networks, and a 51% limited partnership in Motion Picture Distribution LP - Canada's leading film distributor.
Headquartered in Toronto, Alliance Atlantis operates (as of the early 2000s) offices in Montreal, Halifax, Los Angeles, Madrid and Barcelona (Spain), Dublin (Ireland), London (UK) and Sydney (Australia), making it one of the Canada's most dynamic media companies.
