Lahontan came to Canada with the French army in 1693 to take part in expeditions against the Iroquois. First mentioning Newfoundland in an account of the voyage from France, he wrote:"...a storm... where the waves swell prodigiously, even when the winds are low" (Lahontan's Voyages). In 1692 he stopped at Placentia to gather some Basque fishing boats he was escorting to France and while there helped Governor Membeton de Brouillan to defend Placentia against an English attack. This led to his appointment as King's lieutenant of the colony. But animosity between him and the governor obliged him to flee Placentia only six months after taking up his position. He was officer in the colonial regular troops and King's lieutenant at Placentia (Plaisance) in 1693. Lahontan was author of voyages, memoirs, and philosophical dialogues. In 1703 he published an account of his travels in three volumes; Nouveaux voyages de M. de Baron de Lahontan dans l'amerique septentrionale DCB II, EC VI, and Lahontan's Voyages (1932).
Lahontan was believed to have died in 1715.