Castlereagh, ROBERT STEWART, VISCOUNT, was born 18th June 1769, the son of an Ulster proprietor, who in 1789 was created Baron Londonderry, in 1795 Viscount Castlereagh, in 1796 Earl, and in 1816 Marquis, of Londonderry. Robert was educated at Armagh, and, after a twelvemonth at St John's College, Cambridge, was making the grand tour of Europe when in 1790 he was summoned home to enter the Irish parliament as Whig member for County Down—the election cost his father £60,000. He turned Tory in 1795, and next year became Keeper of the Privy Seal; but he continued a steadfast supporter of Catholic emancipation. Still, he believed that emancipation with an independent Irish parliament would mean simply a transference of tyranny from the Protestant oligarchy to a Catholic democracy; hence, as Chief-secretary from 1797, he bent his whole energies to forwarding Pitt's measure of Union. That measure was carried in 1800, largely through Castlereagh's skill in buying up the borough-mongers; but Pitt's pledges to the Catholics were defeated by George III.'s bigotry, and Castlereagh with Pitt retired from office.
Transferred by the Union from Dublin to Westminster, he accepted office in the weak Addington ministry (1802) as President of the Board of Control; but the true second era in his career was as War Minister under Pitt from July 1805 to January 1806, and again under Portland from April 1807 to September 1809. The bombardment of Copenhagen and seizure of the Danish fleet, the extension of the war to the Peninsula, and selection of Wellesley for general, may be set off against the disastrous Walcheren expedition; and even that was a brilliant conception, marred only by the king's obstinacy in giving Lord Chatham the command. Anyhow, Castlereagh was made the scapegoat, and the shilly-shally behaviour of his colleagues caused him to challenge his great rival, Canning. On 21st September 1809 they met upon Putney Heath, and, at the second fire, Canning received a slight wound in the thigh, whilst Castlereagh escaped with the loss of a button.
His real greatness begins with March 1812, when, as Foreign Secretary under Lord Liverpool, he became the soul of the coalition against Napoleon, which, during the momentous campaigns of 1813-14, was kept together by him, and by him alone. 'Time,' Mr Green acknowledges, 'has long ago rendered justice to Castlereagh's political ability, disguised as it was to men of his own day by a curious infelicity of expression; and the instinctive good sense of Englishmen never showed itself more remarkably than in their preference at this crisis of his cool judgment, his high courage, his discernment, and his will, to the more showy brilliancy of Canning.' He represented England at the congresses of Chatillon and Vienna (q.v.) in 1814-15, at the treaty of Paris in 1815, at the congress of Aix-la-Chapelle in 1818; and he was preparing to start for a congress at Verona, when, on 12th August 1822, in a fit of insanity, he committed suicide with a penknife at Foots Cray, his Kentish seat.
England and Europe owe much to Castlereagh for the forty years' peace that succeeded Napoleon's downfall. Yet no statesman, save Stafford, was ever pursued with more rancorous hatred—a hatred that raised a shout of exultation as he was borne to his grave in Westminster Abbey. Mr Green notwithstanding, to many even at the present day he is still the cold-blooded repressor of the Irish rebellion, the 'executioner in enamel,' the sympathiser with the Holy Alliance, the tool of Metternich, Queen Caroline's persecutor, and the author of the Peterloo massacre and the coercive 'Six Acts' which, if the words of our former edition were true, 'will for ever stamp his name with infamy.' His failings have been exaggerated, his splendid services in diplomacy lost sight of or tardily recognised; but, in truth, as a minister, Lord Castlereagh was not lovable.
He had succeeded his father as second marquis in 1821, and leaving no issue by his accomplished wife, a daughter of the Earl of Buckinghamshire, whom he married in 1794, was himself succeeded by his half-brother, Sir Charles Stewart (1778-1854), a gallant soldier, a diplomatist, a statesman, a military historian, and the founder of Seaham Harbour. He it was who edited Lord Castlereagh's Correspondence and Despatches (12 vols. 1847-53), to which reference should be made, as also, with caution, to Sir Archibald Alison's Lives of Lord Castlereagh and Sir Charles Stewart (3 vols. 1861).