The Assiniboine, along with the Stoney of Alberta, share a common ancestry with the Sioux nation. While it was formerly believed that the Assiniboine originated among the Yanktonai division of the Dakota Sioux, linguistic analysis indicates that the Assiniboine and Stoney together form a group coordinate with that of the Santee, Lakota, and Yankon-Yanktonai, and that they are no more related to one of these subdivisions than another. The separation of the Assiniboine from the Sioux must have occurred at some time prior to 1640, as Paul Le Jeune names them along with the "Naduessi" (Sioux) in his Jesuit Relations of that year.