Which French fort on Lake Ontario did Bradstreet's expedition capture in 1758?

The French fort on Lake Ontario captured by Bradstreet’s expedition in 1758 was Fort Frontenac.

Fort Frontenac stood at the mouth of the Cataraqui River, near present-day Kingston, Ontario. Founded in 1673, it functioned as both a military post and a trading center, linking French settlements around the Great Lakes with the St. Lawrence River and the interior fur trade.

Lieutenant Colonel John Bradstreet attacked the fort in August 1758 with more than 3,000 men, mostly provincial militia. The lightly defended garrison surrendered after a short siege on August 28. The British seized supplies, ships, artillery, and trade goods, then destroyed much of the fort before withdrawing.

Fort Niagara was a different French stronghold, captured in 1759. Fort Rouillé was near modern Toronto and was abandoned and burned by the French after Niagara fell. Fort Lévis was a later French position on the St. Lawrence, not the target of Bradstreet’s 1758 expedition.