Heuston, Seán (John J.) (1891–1916), revolutionary, was born 21 February 1891 in Dublin, the son of John Heuston, clerk, and Maria Heuston (née McDonald) of 24 Lower Gloucester St. Educated locally by the Christian Brothers, he did well in the Intermediate examination and in 1908 began working for the Great Southern and Western Railway Company as a clerk and was posted to Limerick. In 1910 he joined Fianna Éireann, the republican boy scout movement, and helped build up a Fianna troop in Limerick of over 250 boys. Transferring to Dublin in 1913 with the GSWR, he continued to work with the Fianna, becoming vice commandant of its Dublin brigade and director of training on its headquarters staff. In November 1913 he was a founding member of the Irish Volunteers. A close associate of Con Colbert (qv), he instructed Fianna members in drill and musketry at Patrick Pearse's (qv) school at St Enda's. In July 1914 he led the Fianna contingent at Howth that unloaded hundreds of Mauser rifles from the Asgard.
By 1916 he was captain of D Company, 1st Battalion of the Irish Volunteers’ Dublin Brigade. At the outbreak of the Easter Rising, he mobilised his men at Mountjoy Square on Monday, 24 April, and, after a circuitous march to the quays, seized the Mendicity Institute (a decaying eighteenth-century building on Usher's Island used as a poorhouse). With about fourteen men, Heuston ordered out its occupants and began to fortify the building. In taking this action he appears to have been acting on the direct orders of James Connolly (qv), commandant-general of the Dublin forces who was based in the GPO, rather than his battalion commandant Edward Daly (qv), whose headquarters was just across the Liffey at the Four Courts. Soon after seizing the building, his men opened fire on a British unit marching down the North Quays, killing an officer and wounding nine men. The Mendicity Institute was a key position in preventing troops who had arrived at Kingsbridge station from linking up with other units in the city centre. Heuston's men defended the building tenaciously and were reinforced by a dozen men sent from the GPO. Over the next two days they came under heavy fire and were surrounded by hundreds of troops. By Wednesday 26 April the besiegers were close enough to throw grenades into the building wounding several Volunteers. Heavily outnumbered, his men hungry, exhausted, and short on ammunition, Heuston expected to be overrun at any moment. At about midday on Wednesday he decided to surrender (despite the protests of some of his men) and his unit was taken to Arbour Hill detention barracks.
On 4 May he was tried by court martial at Richmond barracks. During his trial he strongly challenged the validity of the documentary evidence produced by the prosecution, but was found guilty and sentenced to death. Although a relatively junior officer, Heuston probably received a death sentence because he had held an independent command and inflicted significant casualties on British forces. Lodged in Kilmainham Gaol, on the eve of his execution, Sunday, 7 May, he was visited by his mother, his sister Theresa, his brother, Fr Michael Heuston, OP, and Fr (later Cardinal) Michael Browne (qv), who later remarked that Heuston seemed ‘quite serene’ (MacLochlainn, 113). He wrote a last letter to his sister Mary, a Dominican nun, stating that he had no regrets about his actions and that the independence of Ireland was there for the taking if the Irish people wanted it badly enough. Attended by the Capuchin priest Fr Albert (Thomas Francis Bibby 1877–1924), he was shot by firing squad at Kilmainham jail on 8 May 1916 and buried at Arbour Hill.
Small collections of papers relating to Heuston are held in the NLI and Kilmainham jail. A statue (1943) by Laurence Campbell (qv) stands in the People's Gardens in the Phoenix Park. In 1966 Kingsbridge Station was re-named Heuston Station and the King's Bridge over the Liffey re-named Heuston Bridge.