For over three centuries, the Straits of Mackinac have been occupied by military establishments. Fort de Buade was built by the French in 1681, a decade after Marquette had established his mission in 1671 and called it St. Ignace. Its name was that of the family of Frontenac, the French Governor of North America. Until Detroit was founded in 1701, it was the first and most important French post west of Montreal, guarding the life lines of the fur trade. The fort's commandant had charge of all other French forts in the West. Also known as Fort Michilimackinac, it was the first of three forts which were to bear this name and make up the triangle of history of the Straits area.