Fitzgibbon, John Charles Henry (1829–54?), Viscount Fitzgibbon and soldier, was born 2 May 1829 at Mountshannon House, Castleconnell, Co. Limerick, the only legitimate son of Richard Hobart Fitzgibbon, 3rd earl of Clare, and his wife Diana, daughter of Charles Brydges Woodcock, and formerly wife of Maurice Crosbie Moore. He matriculated at Christ Church, Oxford, in October 1846 but never took a degree. In March 1850 he was commissioned as a cornet in the 8th Royal Irish Hussars, and was promoted to lieutenant in June 1851. Despite being the heir to his father's title and estates, he volunteered for service at the outbreak of the Crimean war in 1854 and was present at the battle of the Alma. He took part in the charge of the Light Brigade on 25 October 1854 and several members of his regiment saw him being hit in the chest simultaneously by two rifle bullets. Two men went to his aid but he urged them to go on and they later stated that he was at the point of death. His body was not recovered after the charge, however, and he was initially posted as missing. The Russians did not include his name in the list of men they had captured, and it was concluded that he had been killed and buried in the field. His name was included in the final casualty list. One trooper later claimed to have passed him, badly wounded but still alive, while returning up the valley, and rumours began to circulate that he had been captured and sent for some reason to Siberia. Both the War Office and the Russian general staff totally discounted such claims. When his father died in January 1864, his title became extinct.
There was a curious epilogue to his story. Fitzgibbon had some distinctive features and was quite tall, had a cast in his left eye, and often wore a monocle. In 1877 a man matching this description visited the regimental mess of the 8th Royal Irish Hussars, then stationed in Hounslow, Middlesex, and several of the officers later stated that this man was Fitzgibbon. Newspapers carried the story, claiming that he had returned from Russian captivity. His family placed notices in the national press appealing for more information or for this man, if he was Viscount Fitzgibbon, to come forward. The notices were not answered, and in November 1877 they had another notice placed in The Times discounting the story as a mischievous rumour. In 1892 an elderly man visited the regimental mess while the regiment was stationed on the north-west frontier of India. Once again the man was described as matching Fitzgibbon's description and knowing all the regimental mess traditions. Some officers stated that they were certain that this was Fitzgibbon but were discouraged from repeating the story. These events inspired Rudyard Kipling's short story ‘The man who was’.
In 1855 a monument was erected to Viscount Fitzgibbon on Wellington Bridge (latterly Sarsfield Bridge) in Limerick city. This was dynamited in 1930.