HMS Endymion was a 21-gun Ister-class wooden screw frigate, the third of four ships of this name to serve in the Royal Navy.

Endymion then served as a guard ship at Hull, Yorkshire until 1879, latterly with her boilers condemned as unfit for service.

During her time at Hull, crew from Endymion assisted the local police in fighting a number of fires in buildings and timber yards.

Emdymion was lent to the Metropolitan Asylums Board in 1881 for use as an administration and hospital ship, initially at Greenwich, Kent and later at Dartford.

He was found guilty and dismissed from the ship, being returned to the United Kingdom on board HMS Megaera.

During the voyage from Rio de Janeiro, a fatal case of yellow fever was reported on board one of the ships.

On 9 November, the squadron was caught in a storm and scattered, with all ships sustaining some damage to their rigging and sails.

[88] Endymion departed from Portsmouth under steam on 6 February 1871 for trials off Spithead, returning to port that day.

[101] On 11 May 1872, Endymion was inspected at Portsmouth by Admiral Sir George Mundy KCB, before departing for Portland that evening.

[106] The engineer of HMS Hart was sentenced to be dismissed from the ship with the loss of a year's seniority and a severe reprimand.

[108] It arrived off Lisbon on 24 September,[109] Endymion left the squadron at Gibraltar, sailing on 7 October for England in company of Aurora.

[96] Endymion was carrying Sir J Drummond Hay, and took him to Tangier, Morocco, leaving immediately after he had disembarked.

[114] On 5 November, a court-martial was held at Portsmouth on board Duke of Wellington of a boy who was accused of the theft of £8 7s 6d belonging to No.7 mess and its caterer.

[115] On 11 January 1873, a court-martial was held at Portsmouth on board HMS Duke of Wellington of an able seaman from Endymion who was charged with desertion and attempting to obtain money by fraudulent means.

[137] Rear-Admiral Randolph, in charge of the squadron, was court-martialled on board HMS Royal Adelaide at Devonport.

[140] After a spell on guard off the Isle of Wight, where Queen Victoria was staying at Osborne House,[141] she arrived at the Medway on 23 July for paying off.

[149] On 1 April, a court-martial was held on board Duncan at The Nore of a marine serving in Endymion who was accused of assaulting a corporal in the execution of his duties.

[152] In September, she was towed from Sheerness to Devonport by the Admiralty tugs Camel and Grinder,[153] her boilers having been condemned as unfit for service.

[152] It was intended that Endymion would be stationed at Harwich, Essex where she was to replace HMS Penelope as the flagship of the Admiral Superintendent of the Naval Reserve.

[155] On 13 December, a court-martial was held on board Duke of Wellington at Portsmouth of an able seaman from Endymion charged with three counts of insubordination and disobedience.

[156] On 23 February 1876, a private in the Royal Marines serving on board Endymion was court-martialled on a charge of insubordination; he pleaded guilty and was sentenced to two years' imprisonment.

[157][158] On 7 March, a fire broke out in the yard of Humphrys & Pearson Ltd, shipbuilders, located in the Victoria Dock.

[168] In March 1879, a butcher in Hull launched a lawsuit to recover £47 in respect of meat supplied to the officers of the wardroom mess.

The jury found in favour of the plaintiff, even though notices had been placed in the local press stating that Jones was not authorised to pledge the credit of the officers on board Endymion.

[171] She arrived at Chatham on 10 July 1879 to be replaced on the Humber by HMS Audacious, with her crew transferring to that ship,[172] including Captain Woollacombe.

[5] In June 1881, the Lords of the Admiralty agreed to lend HMS Atlas and Endymion to the Metropolitan Asylums Board along with a steam pinnace, due to an epidemic of smallpox in London.

[178] The location of the ships drew an objection from the shipbuilders Messrs Rennie because some of their employees refused to work near the riverside where Atlas was moored.

[179] In 1882, the Thames Conservancy wrote to the Metropolitan Asylums Board urging them to move Atlas and Endymion from Greenwich.

The Thames Conservancy also called upon the board to pay a large claim for expenses incurred by Messrs Rennie's.

The Metropolitan Asylums Board decided that the ships provided a useful facility and that they would be kept;[181] in 1883, they were moved downstream to Long Reach, near Dartford.