Eighteenth-century historical documents fail to support the accepted view that the Cree and Assiniboin invaded the West after 1690 as a result of the introduction of the fur trade. This view, widely supported by 19th century authorities, can be traced to several brief ambiguous statements published in 1801 by Alexander Mackenzie. The western limits of the Cree and Assiniboin in the early 1700s remain unclear. Their marauding activities against members of the Blackfoot Confederacy began in the late 1700s, almost fifty years after they were documented as living peacefully in central Alberta. Although their northern limits are unknown, the Cree always seem to have had strained relations with the neighboring Athapaskans. In the mid-1700s, six major Cree groups inhabited the western parklands, plains and boreal the Susuhana, Sturgeon, Pegogamaw, Keskachewan/Beaver, Athabaska, and Missinipi. These groups were all obliterated by the smallpox epidemic of 1781, and nineteenth century observers noted the resultant population shifts.