In the beginning of 1802 he had been mado a privy-councillor of Great Britain, and President of the Board of Control; and he retained that office after Mr. Pitt retired and throughout the Addington admin istration. After Mr. Pitt returned to power, Viscount Castlereagh was, in July 1605, promoted to be one of his majesty's principal secretaries of state (taking the department of War and the Colonies). He was now however thrown out of the representation of Down, but obtained a seat for the borough of Boroughhridge, for which he was returned In January 18013, on a vacancy made by the death of the Hon. John Scott, sou of Lord Eldou. He resigned with the rest of the cabinet on the death of Mr. Pitt shortly after this; and to the next parlia ment, which met in December, with a new ministry, he was returned for the borough of Plympton Earle.
Upon the formation of the Portland administration, in April 1807, Lord Castlereagh was reappointed to his former office of secretary of state; and he was again returned for Plympton to the parliament which met in May of this year. He was now considered the indi vidual principally answerable for the conduct of the war; and the failure of the disastrous expedition to Walchemen In the summer of 1809 not only drew upon him much general unpopularity, but Involved him in a personal quarrel with his colleague Mr. Canning, the secretary for foreign affairs, which led first to the resignation of both, and then to a duel between them, in which Canning, on the second fire, was severely wounded. In the earlier part of this same year also, seine sensation had been made by two reports of select committees of the Commons, which charged Lord Castlereagh, along with other persons, the one with corrupt practices in obtaining the returns of members for Irish boroughs, the other with irregularities in the disposal of Indian patronage.
Lord Castlereagh remained out of office till February 1812, wimp, on the resignation of the Marquis 'Wellesley, he was appointed secre tary of state for tho foreign department. After the death of Mr. rerceval, which followed in May, he was regarded as ministerial leader in the Commons. To the new parliament which met in November 1S12 he was once more returned as representative for the county of Down ; and ho also retained that seat iu the next two parliaments, which met in August 1818 and in April 1820. The return to office of Mr. Canning however, in 1816. had relieved him from a considerable part of his labelers in the conduct of public bueiness in the House, till that gentleman again retired iu 1620.
Meanwhile In the end of the year 1813 Lord Castlereagh had gone as British plenipotentiary to take pert In the neguciatione opened with the French government at Chiltillou, which however broke off after a few weeks without any result ; and he had also appeared as representative of the king of England at the Peace of Paris In May 1314 ; at the Congress of Vienna in October of the same year ; at that of Paris after the battle of Waterloo in the following year ; and at that of Aix-la-Chapelle in 1818. On such occasions as these his fine figure and grace of
manner showed to great advantage. He likewise attended George IV. to Ireland in 1820, where he had for the moment the gratification of being extremely popular among his countrymen. He had been made a Knight of the Garter in le18, and he became Marquis of London derry by the death of his father on the 8th of April 1821.
Lord Londonderry, who had for some time shown symptoms of mental disease, died by his own hand at his seat of North-Cray-1-'lace, in the county of Kent, on the 12th of August 1822. The coroner's jury which at upon the body brought in a verdict of lunacy. Ho had married In 1794 Lady Emily-Anno Hobart, youngest daughter of John, second Earl of Buckinghamshire, but he died without issue, and the title went to his haltbrother, the subject of the following notice.
There was no brilliancy of intellect in Lord Londonderry, scarcely oven the ordinary amount of literary cultivation and taste. His speaking, though fluent, and sometimes spirited, was always Inelegant and slovenly, and occasionally so to a ludicrous degree. To any acquaintance with the philosophy of politics he made no pretension ; nor did even his practical views commonly evince any superior sagacity.
But he had great business talents; and that qualification, with his charm of manner, fitted him admirably for managing men, and was the main secret of his success in life. Something too however is to be attributed to certain moral qualities which ho possessed. Whatever difference of opinion might be entertained about some of his political proceedings or acts done in his political capacity, his personal charac ter was admitted by all who knew him to be that of an honourable and high-minded man, upon both whose firmness and fearlessness every reliance could in all circumstances be placed. His integrity iu this sense had even something of a roughness or sternness that might almost be said to contrast with the amenity of his manner.
"The Correspondence of Robert, Second Marquis of Londonderry,' WAS edited by his brother, the third marquis, in 1850.