enrolled himself among the Irish volunteers. Soon afterwards he entered Trinity College, Dublin, of which his father had been a scholar in 1768 (Cat. Dublin Graduates), but he did not graduate. In 1790 he kept his terms at Lincoln's Inn. On his return to Ireland he took up his residence at Belfast. He was called to the Irish bar, and obtained a good practice on the north-eastern circuit. He took some part in politics on the nationalist side, although his ‘interests, connexions, and hopes lay with the court party.’ At Belfast he wrote for the ‘Northern Star,’ and some of his contributions were circulated as pamphlets. They gave great offence to the Irish government, and a mock review of a pretended epic, ‘The Lion of Old England,’ caused irritation in the army. When the proprietors of the ‘Northern Star’ were indicted for libel, in May 1794, Sampson acted as junior counsel, with John Philpot Curran as his senior. In the following year he was associated with Curran and Ponsonby in the defence of the Rev. William Jackson (1737?–1795) [q. v.], and published a report of the trial. Subsequently he was engaged with Curran in the defence of William Orr [q. v.] for administering the oath of the United Irishmen. Sampson himself, like Thomas Addis Emmet, took the oath in open court, ‘because I hated dissimulation.’ Nevertheless, he wrote afterwards, ‘I was long, very long, in taking any part, and was never much in any secret.’ He seems to have for some time deprecated violent measures.
In 1796, in a pamphlet entitled ‘Advice to the Rich,’ he predicted the Irish union, and tried to show that the government was stimulating rebellion with a view to bringing it about. At public meetings held in Belfast on the receipt of the news of the approach of the first French expedition to Ireland, Sampson gave proofs of his loyalty. At the second meeting, on 2 Jan. 1797, he took the chair and put resolutions in which it was declared that a reform in parliament, ‘without distinction on account of religion,’ would satisfy the public mind. To these moderate resolutions there was appended a request to government for permission ‘to arm, in like manner as the volunteers,’ against the French. A petition of the Irish bar to the same effect, drawn up on 17 May of the same year, and bearing the names of Francis Dobbs, Henry Flood, and George Ponsonby, was signed by Sampson (Grattan, Life of Grattan, iv. 299).
But Sampson's attitude failed to satisfy the Irish government. He was known to be the writer of letters signed ‘Fortesque’ in the ‘Press,’ the Dublin organ of the United Irishmen. He was a prime mover in a society formed for obtaining authentic information as to outrages by the military in Ireland. The society met chiefly at Lord Moira's house in Dublin, and all the leading members of the Irish parliamentary opposition were members of it. Some of the documents collected by the society were privately printed in London. In 1797 and 1798 Madden had the collections in his possession (United Irishmen, 2nd ser. ii. 355–8 and notes). Sampson, in his ‘Memoirs,’ states that he declined Moira's offer to take him to England and provide for him in order to save him from impending danger.
On 12 Feb. 1798 an abortive charge of high treason was brought against Sampson by the aldermen of Dublin for attempting to protect from the soldiery the house of his client Stockdale, printer of the ‘Press.’ In March a false report was circulated that he held a French general's commission, and an attempt was made to arrest him. He escaped, but wrote offering to surrender on promise of a fair trial. Receiving no answer, he fled to England on 16 April, but was arrested at Whitehaven and sent to Carlisle gaol. On 5 May he was taken back to Dublin, where he was confined for several months, first in the Castle tavern, and afterwards in the Bridewell. He was never brought to trial.
Sampson was now approached on behalf of the Irish government with a view to mediating between it and the other state prisoners. He declined the proposal, but in order to save the life of his friend Oliver Bond [q. v.], he agreed, with the other prisoners, at Cornwallis's suggestion (Cornwallis Corresp. 2nd ed. ii. 381), to give all information concerning their organisation and go into voluntary exile, on condition that Bond's life were spared. Sampson's release was delayed for some time; but early in 1799, in accordance with the agreement, he arrived at Oporto. After living quietly for some time there, Sampson was arrested on 12 March 1799, by order of the English ministry, on suspicion of writing ‘Arguments for and against a Union considered,’ a pamphlet against the union. This was in fact by Edward Cooke [q. v.], the Irish under-secretary. In May he was shipped on board a Danish dogger at St. Sebastian, and obtained a passport to Bayonne. Thence he proceeded to Bordeaux, near which place he remained under the close surveillance of the municipality for some eighteen months. From the winter of 1800 till May 1805 he was in Paris, and after spending