Dictionary of National Biography, 1885-1900/Johnson, John Mordaunt
JOHNSON, JOHN MORDAUNT (1776?–1815), diplomatist, was a native of Dublin. He is said to have matriculated at Trinity College, Dublin, and afterwards at Trinity College, Cambridge, but left each university without taking any degree. His father dying in the spring of 1798, Johnson left Cambridge, and was gazetted an ensign in the 51st regiment of foot on 20 Sept. 1798. In January 1779 he purchased a lieutenancy in the same regiment, but, becoming disgusted with the monotony of barrack life, sold out in the autumn of the following year. He then went on the continent, where he became acquainted with the Duke of Brunswick, and ‘made himself perfect master of almost all the modern languages’ (Memoir, p. iii). In the spring of 1803 he returned to England, and subsequently went to Dublin, where he remained until the autumn of 1804. Going once more abroad, he spent three years ‘chiefly in Germany, cultivating the valuable connections which he had formed on his first excursion to the continent, and acquiring information on all subjects of continental policy’ (ib.) In the hope of obtaining an official appointment, he returned again to England, and became involved in financial embarrassments. Subsequently Spencer Perceval's attention was drawn to his abilities by the manuscript of ‘A Memoir on the Political State of Europe,’ which Johnson had written with a view to publication. After an interview with the prime minister Johnson obtained employment in the foreign office, and was constantly employed in confidential missions to the continent. After the peace of Paris of 1814 he was appointed British chargé d'affaires at Brussels, and upon the union of the Netherlands with Holland was promoted to the post of British consul at Genoa. He died at Florence, whither he had removed for the benefit of his health, on 10 Sept. 1815, aged 39, and was buried in the cemetery attached to the British factory, near Leghorn, on the following day. Johnson was unmarried. He was a man of agreeable manners, an excellent linguist, and remarkable for the extent and accuracy of his political information. He is said to have been ‘in close and friendly correspondence with the principal ministers and generals and leading public characters of almost all the states of Europe’ (ib. p. ix). A few extracts from some of his letters to his friends are appended to the memoir prefixed to ‘Bibliothecæ Johnsonianæ Pars Prima,’ 1817 (pp. xii–xxiii), and four of his letters on foreign politics are given in ‘The Correspondence and Despatches of Viscount Castlereagh,’ 1853 (3rd ser. i. 340–1, 350–1, 362–4, 503–4). He appears to have assumed the additional name of Mordaunt after leaving the army, as he is described as John Johnson in the ‘Army List.’ The first part of his library was sold by Evans of Pall Mall in June 1817.
[Bibliothecæ Johnsonianæ Pars Prima, 1817, containing a prefatory Memoir of Johnson; Gent. Mag. 1815 pt. ii. pp. 377, 1817 pt. i. pp. 521–6; Army Lists, 1780, 1799.]