In the late eighteenth century midshipmen (‘young gentlemen’ aspiring to become commissioned officers) usually joined the British navy through patronage or ‘interest’: string-pulling. You got your berth under a captain your family had connections with. After six years of notionally voluntary service a midshipman who successfully completed a formal examination could be promoted to lieutenant. There was no system of purchased commission as in the army: this meant that a naval career could be open to boys of less wealthy families and to younger sons of the rich who were destined not to inherit.

Rowland Mainwaring joined the navy in 1795 as a midshipman on the Jupiter under Captain William Lechmere. Recording his promotion to captain in 1832, the Royal Naval Biography notes that Rowland’s initial engagement was through the patronage of Admiral Sir John Laforey. I do not know how the Mainwarings were connected either to the Lechmere or to the Laforey families.

Rowland was one of five cousins who joined the navy about this time. With the exception of Jemmett Mainwaring (1763 – 1800), a first cousin of his father, no member of this branch of Mainwaring family had ever followed a naval career.

Abbreviated family tree: The grandson and great grandsons of Edward Mainwaring and Jemima Mainwaring nee Pye who joined the British navy are highlighted in blue.

Jemmett Mainwaring born 1763 was the youngest son of of Benjamin Mainwaring (1719 – 1782) who had three sons who survived to maturity . Jemmett’s oldest brother Edward (1744 – 1803) served as an officer during the first American war. The second brother, John Montague Mainwaring (1761 – 1842), also served in the army rising to the rank of Lieutenant-General.

Jemmett seems to have obtained a midshipman’s place no later than 1783. It was a requirement at the time that before being commissioned as a lieutenant, an officer had to serve six years at sea and pass an examination. Jemmett Mainwaring was commissioned as a lieutenant in 1789 when he was 26.

I have found no record of his career before he was lieutenant nor do I know who his patron was. However, Jemmett Mainwaring’s grandmother, Jemima Mainwaring nee Pye (1681 – 1721) had a nephew, Thomas Pye (1708 – 1785), an admiral. Although Jemima was no longer alive to exert any influence on behalf of her grandson, perhaps Jemmett’s father Benjamin appealed to his maternal cousin on his behalf. Jemmett was a younger son, with two surviving older brothers. His father was also a younger son. A naval apprenticeship for Jemmett, with the likelihood of a commission, must have seemed an attractive prospect, potentially very rewarding.

The Royal Navy was expanded rapidly, especially at the time of the French Revolutionary Wars of 1792 – 1801. In 1784 there were 2,230 officers of whom 1,499 were lieutenants. In 1800 there were 3,168 officers of whom 2,120 were lieutenants; increases of over 40%. Moreover, in 1784 only about 25% of officers were serving afloat. In 1800 60% of officers and 68% of lieutenants were serving afloat.

Jemmett Mainwaring’s first placement as a lieutenant, from June 1789, was on HMS Royal George, a 100-gun first rate ship of the line, launched at Chatham Dockyard the year before Jemmett Mainwaring joined her. It appears that he served on the Royal George until 1795. 

HMS Royal George on the right fitting out in the River Medway off what is now Sun Pier, with HMS Queen Charlotte under construction in the centre background. This is a view from Chatham Ness, today the southernmost point of the Medway City Estate. Artist: Nicholas Pocock. Image retrieved from Wikimedia Commons.

Jemmett Mainwaring may have been on the Royal George at the Glorious First of June, also known as the Fourth Battle of Ushant of 1794. This was the first and largest fleet battle during the French Revolutionary Wars. The French admiral, Rear-Admiral Louis-Thomas Villaret-Joyeuse, had sailed from Brest to intercept a valuable grain fleet from America, urgently needed in famine-stricken France. The English commander-in-chief, Lord Howe, sailed with the Channel Fleet to intercept the convoy; neither the French battle fleet nor the British encountered the convoy, which reached Brest in safety. Instead the two battle fleets made contact on 28 May, some 365 nautical miles (673 km) off Ushant, Brittany.

Only a few British ships managed to pierce the French line and engage closely with the enemy. The Royal George, Admiral Hood‘s flagship, was one of these. It engaged closely with two French ships but lost its foremast and suffered damage to the rigging during the battle.

Map of the position of the ships of the British Royal Navy and the French Navy at the start of their battle on 1 June 1794. Image from Wikimedia Commons: authors users Ruhrfisch and Maxrossomachin
Philip James de Loutherbourg: The Battle of the First of June, 1794 retrieved from Wikimedia Commons
The painting shows the duel between the opposing flagships ‘Queen Charlotte’ (Howe, centre left) and the ‘Montagne’ (Villaret-Joyeuse); and also the the sinking of the ‘Vengeur du Peuple’, 74 guns, and the attempts to rescue her crew.

In June 1795 Jemmett Mainwaring was commissioned with the rank of commander and was appointed to HMS Espiegle, a 16 gun French-built sloop captured by the British in 1793.  When the Royal Navy took her into service they retained her name. Six months later in December 1795 Mainwaring was transferred to the command of HMS Victorieuse.

Victorieuse was a brig of the French Navy, launched at Honfleur in 1794. The British captured her in August 1795 and took her into service as HMS Victorieuse. She was fitted out at Portsmouth dockyard at a cost of £890. On 22 February 1796 she sailed for the Leeward Islands, a group of islands colonised by the British and situated where the northeastern Caribbean Sea meets the western Atlantic Ocean. Victorieuse was at the attack on St. Lucia on 24 May 1796 and was one of the vessels covering the landing of troops at Choc Bay. She shared in the prize money paid in June 1800.

In July 1796 Jemmett Mainwaring was promoted to Captain, with command of HMS Aimable, a 32 gun French frigate built in 1776 and captured by the British in 1782. The Aimable had a complement of 192.

On the evening of 22 July 1796, shortly after taking command, Mainwaring in the Aimable engaged the French frigate Pensee (44 guns and 400 men; Seine class frigate originally named La Spartiate) off Guadeloupe. Although the Pensee was a significantly more powerful vessel, the men of the Aimable were, so it is reported, more than willing to take her on, crying “To glory or to death!” when Mainwaring pointed out the superior force of their opponent. Mainwaring himself said that he would lead them into action against their republican foe with sincere pleasure.

In the exchange the Pensee suffered losses of 28 men killed and 36 wounded. The Aimable had two men wounded. The next morning the Aimable was preparing to capture the Pensee, making preparations to lash the Pensee’s bowsprit to the Aimable’s main mast when the French commander and his crew greeted the British frigate by pulling off their hats and waving them. The British sailors returned this chivalrous salute but then the Pensee sailed away and escaped. Three days later the Aimable arrived at the island of St Thomas, then a Danish colony,  and found the Pensee there undergoing repairs. The British and French commanders subsequently dined together with the Danish Governor.

In other engagements under the command of Jemmett Mainwaring the Aimable captured the French Privateer L’Iris (6 guns) in September 1796 and in April 1797 took the Privateer Le Chasseur (6 guns).

Places in the Carribean associated with Jemmett Mainwaring
19th century miniature portrait of a naval officer auctioned 2014. Item description “19th century miniature portrait of a naval officer, Capt Jemmet Mainwaring”



  • UK, Commissioned Sea Officers of the Royal Navy, 1660-1815 retrieved through
  • Rodger, N.A.M. “Commissioned officers’ careers in the Royal Navy, 1690–1815.” Journal for Maritime Research, vol. 3, no. 1, 2001, pp. 85-129.
    • quoting Naval Promotions (HC 1833 XXIV p.279) p.282
  • Harrison, Cy. “Jemmett Mainwaring (d.1801).” Three Decks – Warships in the Age of Sail,
  • The London Gazette
  • Marshall, John (1825). Royal Naval Biography : Or, Memoirs of the Services of All the Flag-officers, Superannuated Rear-admirals, Retired-captains, Post-captains, and Commanders, Whose Names Appeared on the Admiralty List of Sea Officers at the Commencement of the Present Year, Or who Have Since Been Promoted, Illustrated by a Series of Historical and Explanatory Notes … with Copious Addenda: Superannuated rear-admirals. Retired captains. Post-Captains. Longman, Hurst, Rees, Orme, and Brown. Volume II Part II pp. 600–5. [Biography of John Wight Esq who was lieutenant on the Aimable in July 1796.]
  • James, William (1826). The Naval History of Great Britain from the Declaration of War by France, in February 1793 to the Accession of George IV in January 1820. Harding, Lepard, and Company. pp. 484–6.

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