Action of 29 April 1758
Part of theSeven Years' War
1758 portrait ofLouis de Rohan
Date 29 April 1758 Location Bay of Biscay,Atlantic Ocean Result British victory
Belligerents
Great Britain	France
Commanders and leaders
Peter Denis	Louis de Rohan
Strength
2 ships of the line	1 ship of the line
Casualties and losses
16 killed 20 wounded	61 killed 100 wounded 1 ship of the line captured

Theaction of 29 April 1758 was a naval engagement fought in theBay of Biscay nearBrest between a BritishRoyal Navy squadron and a singleFrench Navyship of the line during theSeven Years' War. In an attempt to support the garrison ofLouisbourg, who were facing an impendingsiege, 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 closeblockade of their main port at Brest. In April a British squadron includingHMSIntrepid,HMSDorsetshire andHMSAchilles was cruising off the French Biscay Coast when a lone sail was sighted to the southwest.Dorsetshire, commanded by CaptainPeter Denis was sent to investigate, discovering the ship to be the French ship of the lineRaisonnable sailing toLouisbourg. In a fierce battle,Dorsetshire managed to inflict heavy casualties on the French ship and force her captain,Louis-Armand-Constantin de Rohan, to surrender.

In 1758 the BritishRoyal NavyChannel Fleet and theFrench Navy Atlantic Fleet were contesting control of theBay of Biscay and theAtlantic Ocean during theSeven Years' War, which had broken out between Britain and France in 1755 over colonial dominance in North America. For the French Navy the priority was maintaining their lines of supply to the majorFrench Canadian fortress ofLouisbourg, which was soon to fall undersiege. To support the city, the French Atlantic Fleet sent squadrons and single ships into the Atlantic to bring supplies and reinforcements to the garrison and the Royal Navy in turn deployed forces to intercept these missions.^[1]

One squadron deployed in closeblockade at Brest in April 1758 was commanded by Captain Edward Pratten inHMSIntrepid. On 19 April, a sail was sighted to the southwest and Pratten detached the 70-gunHMSDorsetshire under CaptainPeter Denis to investigate.^[2] The ship proved to be the 64-gun Frenchship of the lineRaisonnable under CaptainLouis-Armand-Constantin de Rohan,Chevalier de Rohan andPrince de Montbazon. Realising the strength of the French ship, Pratten subsequently detached the 60-gunHMSAchilles under CaptainSamuel Barrington to supportDorsetshire.^[3]

BeforeAchilles could arrive, Denis succeeded in bringingDorsetshire alongside the French ship and in a fiercebroadside engagement successfully forcing Rohan tostrike his colours. Barrington's ship only arrived in range in the final minutes, confirming the French surrender. French casualties were heavy, with 61 killed and 100 wounded, while losses onDorsetshire numbered 15 killed and 21 wounded, one of whom subsequently died.^[2]Raisonnable was subsequently repaired and commissioned into the Royal Navy under the same name, serving until she was accidentally wrecked atMartinique in February 1762.^[4] The Siege of Louisbourg went ahead in June 1758, and the city fell the following month, blockaded from reinforcement by the Royal Navy.^[5]

• Clowes, William Laird (1997) [1900].The Royal Navy, A History from the Earliest Times to 1900, Volume III. London: Chatham Publishing.ISBN 1-86176-012-4.

• Conflicts in 1758
• Military history of the Bay of Biscay
• Naval battles of the Seven Years' War involving France
• Naval battles of the Seven Years' War involving Great Britain

• Articles with short description
• Short description matches Wikidata
• Use dmy dates from February 2018