Dillon, Thomas, fourth Viscount Dillon 1615?-1672?, was the second son of Sir Christopher Dillon, president of Connaught, and Lady Jane, eldest daughter of James, first earl of Roscommon. He was bred a Roman catholic, but when, at the age of fifteen years, he succeeded his nephew, Theobald, the third viscount, 13 May 1630, he declared himself a protestant. He was present in the parliament of Dublin 16 March 1639-40, and in 1640 was made a lord of the privy council. In November 1641 he was appointed, along with Lord Viscount Mayo, joint governor of county Mayo. On 13 Feb. 1641-2, he was chosen, along with Lord Taaffe, by the Irish parliament to present their grievances to the king (Apology of the Anglo-Irish for Rising in Arms in Gilbert, Contemporary History of the Irish Confederation, i. 246-53). Soon after landing in England they were imprisoned by the parliament there as agents employed by the rebels of Ireland to the king, but gradually obtaining the liberty of London, they made their escape after four months, and came to York, whither a messenger from the House of Commons followed them and demanded them as prisoners. The king, however, took no notice of their escape, and having volunteered to serve with the troops, they behaved themselves with good courage, and frankly engaged their persons in all dangerous enterprises (Clarendon, History of the Rebellion, Oxford edition, ii. 218). After his return home, Dillon was made a lieutenant-general, and, along with Viscount Wilmot, was appointed lord president of Connaught. Subsequently he joined the Marquis of Ormonde in command of the army of the confederates, and was left by him with two thousand foot and five hundred horse to block up the city of Dublin in the north. He maintained Athlone till 18 June 1651, when articles of agreement were arranged between him and Sir Charles Coote. At the time of the Commonwealth his estates were sequestrated. In consideration of a sum of money he resigned in 1662 the presidency of Connaught to Charles II, by whom he was appointed custos rotulorum. He died in 1672 or 1673. By his wife, Frances, daughter of Nicholas White of Leixlip, he had six sons.

Sources:
     Borlace's Reduction of Ireland
     Gilbert's History of the Confederation, vols. i. and ii.
     Contemporary History of Affairs in Ireland, 1641-52, ed. Gilbert
     Clarendon's History of the Rebellion
     Gardiner's Hist. of England, vol. x.
     Lodge's Peerage of Ireland (Archdall), iv. 184-9.

Contributor: T. F. H. [Thomas Finlayson Henderson]

Published: 1888