Barnewall, Nicholas (1668–1725), 3rd Viscount Barnewall of Kingsland , soldier, and catholic lobbyist, was born 15 April 1668, son of Henry Barnewall, 2nd Viscount Kingsland of Kingsland, and his second wife, Mary, daughter of Richard Nugent (qv), second earl of Westmeath. Of Old English extraction, he stemmed from a prominent Pale family; he was the grandson of Nicholas Barnewall (qv), 1st Viscount Kingsland. Born shortly before his father's death in June 1668, the infant Kingsland was placed under the guardianship of his uncle Thomas Nugent (qv), later Lord Riverston. In May 1688 he married Mary (d. 1736), youngest daughter of Sir George Hamilton (qv; d. 1676) and his wife Frances Jennings (qv), who later married Richard Talbot (qv), earl of Tyrconnell. Two sons and four daughters survived into adulthood. The marriage was brokered by Riverston, and Kingsland received a marriage portion of £3,000; he himself later inherited lands valued at £3,500.
In 1688 Kingsland entered the army as a captain of dragoons in the regiment of William Dongan (qv), 2nd earl of Limerick. In 1689 he took his seat in the Jacobite parliament. He saw service at the battle of the Boyne in July 1690, and subsequently at Limerick. Initially outlawed for his service in the Jacobite army, Kingsland was, however, one of the twelve Irish peers to retain their lands under the articles of Limerick. On 29 October 1692 Kingsland produced his writ and sought to take his seat in the Williamite parliament. While he took the oaths newly prescribed for admission to parliament, he refused to subscribe to the relevant declaration of loyalty to William III (qv) and was forced to withdraw. On 2 December 1697 the reversal of his outlawry was confirmed by the lords, but in June 1700 he was accused of signing a petition to James II (qv), asking that troops be sent over to Ireland in the light of burgeoning Jacobite support in the country. On 28 February 1703 he was one of a number of prominent catholics to bring a petition before the Irish house of lords registering their opposition to the ‘act to prevent the further growth of popery’. However, while the petitioners were subsequently heard before the bar of the house, the act was passed without amendment. On 20 August 1709 he was a leading signatory in another catholic petition, registering opposition to the 1709 act amending the 1703 popery act. On 14 December 1715 Kingsland again produced his writ and sought to take his seat in the new parliament. But although he took the oath of allegiance, he refused to subscribe to the other oaths and the declaration; again, he was forced to withdraw. He appears to have made no attempt to reenter political life after 1715.
Kingsland died 14 June 1725, and was buried in Lusk; he was lauded by the Dublin broadsheets for generosity towards his tenants. His eldest son Henry-Benedict (1708–74) succeeded as 4th Viscount Kingland, and also sought to take his seat in the lords. However, as a catholic he too was barred from the house.