The future Lord Nelson served as Agamemnon's captain from January 1793 for three years and three months, during which time she saw considerable service in the Mediterranean.

After Nelson's departure, she was involved in the infamous 1797 mutinies at Spithead and the Nore, and in 1801, she was present at the first Battle of Copenhagen, but she ran aground before being able to enter the action.

She fought at the Battle of Trafalgar on 21 October 1805 as part of Nelson's weather column, where she forced the surrender of the Spanish four-decker Santísima Trinidad.

Her worn-out and poor condition contributed to her being wrecked when, in June 1809, she grounded on an uncharted shoal in the mouth of the River Plate whilst seeking shelter with the rest of her squadron from a storm.

Agamemnon was ordered from the commercial shipbuilder Henry Adams at his Bucklers Hard shipyard on the Beaulieu River on 5 February 1777 to be built to the lines of the Ardent class, as designed by Sir Thomas Slade.

Kempenfelt was ordered to intercept the convoy, which he did in the afternoon of 12 December in the Bay of Biscay, approximately 150 miles (241.4 km) south-west of Ushant.

On 9 April, the Battle of the Saintes began with an indecisive skirmish, in which the ships of the vanguard division, under Hood's command, were severely damaged and forced to withdraw to make repairs.

[2] After the signing of the Treaties of Versailles brought an end to the Anglo-French War, Agamemnon returned from the West Indies to Chatham, where she was paid off and docked on 29 October 1783 for repairs and to have her copper sheathing replaced.

[2] In anticipation of the start of Britain's involvement in the French Revolutionary War after the execution of King Louis XVI, Agamemnon was recommissioned on 31 January 1793.

[2] On 27 August, the town of Toulon declared its allegiance to the Royalist Bourbon cause, and Hood's fleet moved in to take control of the naval dockyard and the 30 French ships of the line in the harbour.

After capturing 19 ships, Agamemnon was sent to Naples to ask King Ferdinand IV for reinforcements to secure the town; he agreed to provide 4,000 men.

When the revolutionary army, commanded by Napoleon Buonaparte, launched its assault against Toulon, the troops proved insufficient to hold it, and they were forced to abandon the town.

[10] After Hood arrived with additional ships, Agamemnon contributed guns and men to the 51-day siege of Calvi, during which time Nelson lost sight in his right eye when a French shot kicked sand and grit into his face.

[12] Agamemnon, still with the Mediterranean fleet—now under Vice-Admiral William Hotham, who had superseded Hood in December 1794—participated in the Battle of Genoa when a French fleet, comprising 15 ships of the line, was sighted on 10 March 1795.

Due to adverse winds, Admiral Hotham was unable to come to her aid until the following day, and the French fleet was sighted again on 13 July, off the Hyères Islands.

Shortly thereafter, in the action of 31 May 1796, boats from Agamemnon and Nelson's squadron captured a small convoy of French vessels off the Franco-Italian coast, while suffering minimal casualties.

[16] In response to developments in the Baltic in 1801 that threatened to deprive Britain of much-needed naval supplies, Agamemnon was sent as part of a fleet under Admiral Sir Hyde Parker and Vice-Admiral Lord Nelson to attack the Danish at Copenhagen.

Instead, after Britain's entry into the Napoleonic Wars, she was brought out of ordinary in 1804, recommissioned under Captain John Harvey on 31 July, and went to join the Channel fleet under Admiral William Cornwallis.

En route, Agamemnon fell in with a French squadron, consisting of six ships of the line and several smaller vessels, which gave chase.

Succeeding in evading the French, Agamemnon joined the blockading squadron on 13 October,[14] and when Nelson laid eyes on the approaching ship he reportedly exclaimed: "Here comes that damned fool Berry!

[19] Once engaged, she was firing both batteries, eventually pounding the great Spanish four-decker Santísima Trinidad until that ship was dismasted and, with 216 of her complement dead, struck her colours.

Before Berry could take possession of the prize, the enemy van division began bearing down on the British line, having previously been cut off from the battle by Nelson's line-breaking tactics.

With Nelson already dying below decks on Victory, Captain of the Fleet Thomas Hardy ordered Agamemnon and several other ships to intercept them.

[20] At the beginning of 1806, Agamemnon was with Vice-Admiral Duckworth's squadron in the West Indies, pursuing a French fleet carrying troops to Santo Domingo.

They had been escorting the merchant vessel Maria, which had carried the surgeon Dr. James Paroissien to Montevideo where he was tasked with exposing a plot against King John VI of Portugal, who was in exile in Brazil.

Agamemnon, along with the rest of the squadron (which was now under the command of Rear-Admiral Michael de Courcy), put into Maldonado Bay for the third and final time, to shelter from a storm.

[28] In March 1993, the wreck was located north of Gorriti Island in Maldonado, Uruguay Bay Punta del Este by sonar operator Crayton Fenn.

Later in 1997, with the help of Mensun Bound documented the remains and recovered several artefacts, including a seal bearing the name 'Nelson,' and one of Agamemnon's 24-pounder guns from her main gundeck.

[25][29][30] The historical novelist Patrick O'Brian selected Agamemnon as one of the ships on which Jack Aubrey served as lieutenant before the events of Master and Commander, the first novel in his Aubrey–Maturin series.