Edgeworth (de Firmont), Abbé Henry Essex (1745–1807), priest, confessor to Louis XVI, was born in Edgeworthstown, Co. Longford, the second son of eight children of the Rev. Robert Edgeworth, landowner and rector of Edgeworthstown. Maria Edgeworth (qv), the writer, was a distant cousin. In 1749 his father converted to catholicism and the family emigrated to France. Henry was educated by the Jesuits at Toulouse, before going to Paris to study for the priesthood. French was his first language, and he spoke English with difficulty. Upon his ordination he took the name de Firmont, from his father's estate of Firmount near Edgeworthstown, his surname being too difficult for the French to pronounce. He was known as the Abbé de Firmont in France, but in English-language sources is usually referred to as the Abbé Edgeworth. He initially intended a career in the missions but was persuaded to remain in Paris and minister to the people of the slums, refusing an Irish bishopric in order to do so. He was bitterly opposed to the French revolution, and in February 1791 he was chosen as confessor to Louis XVI's sister, Princess Elisabeth. She recommended him to her brother during the final days before his execution, and on 20 January 1793 Louis named Edgeworth as his confessor.
It was hoped that his obscurity might save him from persecution, but Edgeworth nevertheless made his will before setting out to attend the king, expecting to be killed afterwards. He stayed with Louis on the night of 20 January, administered communion at six o'clock the following morning, and accompanied him to the scaffold, acting as a calming influence and comparing his humiliations to those of Jesus Christ. He assisted Louis up the steps to the guillotine, before falling to his knees in a state of deep emotion while the execution took place. Legend attributes to him the famous phrase ‘Fils de Saint Louis, montez au ciel’ (‘Son of Saint Louis, ascend to heaven’), though he never recollected saying it, and it was probably invented afterwards. Later he wrote a lengthy account of the final seventeen hours of Louis's life, which remains an important historical document. It was published in 1815 by C. Sneyd Edgeworth as Memoirs of the Abbé Edgeworth: containing his narrative of the last hours of Louis XVI.
His clothes stained with the king's blood, Edgeworth made his escape through the crowd and fled Paris, but he refused to leave France. During the next three years he avoided arrest by living in hiding and moving about all over the country. His family, however, suffered from his loyalty to the crown: his mother was arrested and died in captivity, and his sister was imprisoned for thirteen months. In 1796 he went to Britain and refused a pension from the prime minister, William Pitt, and separately declined the presidency of Maynooth College. For a time he considered retiring to Ireland, but he was persuaded by Louis XVIII, the dead king's brother, to travel to Brunswick carrying confidential documents for him. Once there, he agreed to stay and serve as Louis's confessor, becoming vicar-general of Paris. In 1800 he travelled to Russia to present the czar with the order of the Holy Spirit, and he was awarded a pension of 200 ducats.
In 1805 Firmount was sold, and the revenue lost, leaving Edgeworth penniless. He was obliged to write to Pitt, belatedly accepting his offer of a pension. While ministering to French prisoners at Mittau in Russia, he contracted a fever; he was nursed by Louis XVI's daughter but died there 22 May 1807.