Fort Conti was built in early 1679 at the mouth of the Niagara River on Lake Ontario as a post for the French explorer René-Robert Cavelier, Sieur de La Salle. Because of the fort's location, the French hoped to control the fur trade in the lower Great Lakes. The fort was named after Louis Armand I, Prince of Conti, the patron of La Salle's lieutenant, Henri de Tonti.