Radisson, Pierre Esprit (pyĕr ĕsprēˈ rädēsôNˈ) [key], c.1632–1710, French explorer and fur trader in North America. He arrived in Canada in 1651. His journals, first published as the Voyages of Peter Esprit Radisson (1885), are confusing documents, often leaving great doubt as to the location of places and the time of events. The first journal tells of his capture (1652–53) by the Iroquois. Another asserts that he made (1655–56) a trip to the West with his brother-in-law, Médard Chouart, sieur des Groseilliers, his companion on the later trips; it is probable, however, that only Groseilliers undertook the journey mentioned in this journal. On the second trip (1659–60) the two men entered Lake Superior and went as far west as the Sioux villages near Isanti Lake, the first white men to enter the region that is now Minnesota. They returned with an immense cargo of furs, which were confiscated at Montreal because they had traded without a license. This episode led Radisson and Groseilliers to transfer their allegiance to the English, and, backed by Prince Rupert, they set sail in 1668 for Hudson Bay. Radisson's ship was turned back but Groseillers's continued, and he established Fort Charles at the mouth of Rupert River in James Bay. He returned to England with furs, and in 1670 both men were back at Hudson Bay, Radisson establishing Port Nelson on the Nelson River. It was thus largely because of their efforts and Radisson's stories of the wealth of the north in furs that the Hudson's Bay Company was formed. Later Radisson returned to the French and led a plundering expedition against the English forts on Hudson Bay. He finally (1684) joined the English again and after a long lawsuit was pensioned by the Hudson's Bay Company in his old age.
See G. L. Nute, Caesars of the Wilderness (1943, repr. 1969).