Native peoples have lived in Eeyou Istchee for thousands of years. The Cree communities are composed of subgroups that settled in the second half of the 20th century around the trading posts, some of which had been in operation since the 17th century. The communities themselves differentiate between coastal Crees and inland Crees based not only on the existing geographical locations of the communities, but also on traditional family hunting grounds and linguistic variations.

In the early 1970s, the Crees of the existing nine communities lived in six villages: Great Whale, Fort George, Paint Hills, Eastmain, Rupert House and Mistissini. The Crees of Waswanipi lived not on the reserve of the same name (newly created), but in Waswanipi River, Matagami, Miquelon, Lebel-sur-Quévillon and Chapais. The members of the Nemaska community used the Old Nemaska trading post until it closed in the early 1970s. After that, they moved to Mistissini or Waskaganish. The Oujé-Bougoumou Crees lived in Mistissini or Doré Lake, near Chibougamau.
An overview of Cree society over the past four decades is provided through data related to demography, institutions, infrastructure and services, education and lifestyle. The data was taken from the environmental impact assessment conducted by Hydro-Québec for the Eastmain-1-A powerhouse and Rupert diversion project.