The action of 29 April 1758 was a naval engagement fought in the Bay of Biscay near Brest between a British Royal Navy squadron and a single French Navy ship of the line during the Seven Years' War. In an attempt to support the garrison of Louisbourg, who were facing an impending siege, the French Atlantic Fleet sent a number of squadrons and ships to sea during the spring of 1758. To intercept these ships, Royal Navy squadrons maintained a close blockade of their main port at Brest. In April a British squadron including HMS Intrepid, HMS Dorsetshire and HMS Achilles was cruising off the French Biscay Coast when a lone sail was sighted to the southwest. Dorsetshire, commanded by Captain Peter Denis was sent to investigate, discovering the ship to be the French ship of the line Raisonnable