Robert Stewart (1769-1822) Viscount Castlereagh from 1796. Second Marquess of Londonderry (Ireland) from 1821. Chief Secretary for Ireland, 1798-1801. President of the Board of Control, 1802-6. Secretary of State for War and the Colonies, 1805-6, 1807-9. Foreign Secretary, 1812-22. He was the son of Robert Stewart, a prominent Irish landowner and politician, who achieved four steps in the Irish peerage and sat from 1801 in the House of Lords as an Irish representative peer. Castlereagh’s stepmother (his mother died in childbirth) was the daughter of Charles Pratt, first Earl of Camden (1714-94), giving him an entry into British politics near the top. Castlereagh was educated privately and at St John’s College, Cambridge, making that college second only to Christ Church, Oxford (six Cabinet members and three junior ministers) in Liverpool’s governments, with three Cabinet members (Castlereagh, Harrowby and Robinson) and two junior ministers (Clancarty and Palmerston).
Castlereagh entered the Irish House of Commons for Downshire in 1790, after an election that had reputedly cost £60,000, and joined the Northern Whig Club, thus being expected to act with the opposition. However, first-hand observation of the National Assembly in Paris in 1791 turned him against radicalism and in 1794 he entered the British Parliament in a seat offered by Pitt, and he sat in both Houses of Commons for the next three years.
Camden (the second Earl, Castlereagh’s uncle) became Lord Lieutenant in 1795 and Castlereagh then devoted himself largely to Irish affairs. He appeared to commit to an Irish rather than a British career when he resigned from the British House of Commons on accepting the Irish Privy Seal in 1797. Then, in March 1798, Castlereagh became Acting Chief Secretary for Ireland just before the Irish Rebellion. He arranged for the arrest of the United Irish leaders in May, frustrating their attempt to seize Dublin. He was confirmed as Chief Secretary when Cornwallis succeeded Camden in June 1798.
Castlereagh was an advocate of union between Ireland and Britain, provided it could be carried out on a ‘close Protestant basis’, albeit with emancipation for the Catholics. Accordingly, now a British Privy Councillor, he instituted a programme of winning over Catholics with half promises of Emancipation after Union and the Irish borough owners with ample compensation for their lost patronage. At a cost of £1.26 million, 84 Irish boroughs, including that of Castlereagh’s family, were bought up and in February 1800 the Union proposals were carried in the Irish parliament by a majority of 43 votes in the largest division ever known there. ‘High gallows, and a windy day, For Billy Pitt and Castlereagh’, sang the Irish balladeers; it was less elegant than Shelley’s later ditty, but equally a tribute to Castlereagh’s courage.
When Emancipation was blocked by the King, Castlereagh felt forced to resign with Pitt. However, after a year of rest and a short-lived nervous breakdown, he began his British political career as President of the Board of Control, with a seat in Addington’s Cabinet from October 1802. He lent strength to this much-assailed administration, being a good administrator with a logical mind and a reliable Commons speaker, although not especially eloquent.
When Pitt returned to power, he retained Castlereagh at the Board of Control and then promoted him to War and the Colonies on Sidmouth’s resignation in July 1805. Surprisingly, Castlereagh seems to have lacked a sound grasp of military strategy; his two terms of service in this job were both quite unsuccessful. In 1805 he prepared an expedition to the Elbe that was aborted after Austerlitz, while in 1807-9 he was responsible for the Convention of Cintra and the Walcheren expedition. He was compelled to resign in October 1809 after the exposure of Canning’s scheming led to the famous duel between the two men.
Several attempts to bring Castlereagh back to strengthen the Perceval ministry proved abortive and it was only in March 1812, on Wellesley’s resignation, that he was finally rewarded with the Foreign Office, to which Liverpool added the leadership of the House of Commons.
Castlereagh was a great success after 1812 in both his positions, though the combination undoubtedly placed a heavy burden on him. Commons leadership was no sinecure in the difficult years after 1815, although he had his friend Arbuthnot’s help in managing a fairly stable majority for the Liverpool government. He was unquestionably Liverpool’s right-hand man on all but economic matters, and completely trusted. Conversely, Liverpool exercised a gentle leadership and guidance over him on foreign policy, particularly when Castlereagh was absent at the Congress of Vienna and elsewhere, in which case Liverpool or Bathurst undertook the Foreign Office’s day-to-day business.
On Castlereagh fell the main burden of defending the Liverpool government’s policies in the House of Commons and between 1815 and 1820 that burden was heavy indeed. However, it helped that he was generally liked by those who knew him. Even among the populace as a whole, despite numerous attacks on his townhouse windows, he was never as unpopular as might be implied by Shelley’s1 1819 Mask of Anarchy, written after the Peterloo Massacre:
I met Murder on the way –
He had a mask like Castlereagh –
Very smooth he looked, yet grim;
Seven blood-hounds followed him:
All were fat; and well they might
Be in admirable plight,
For one by one, and two by two,
He tossed them human hearts to chew.
Like the Irish verse, this was another remarkable tribute to Castlereagh’s courage.
As for the unpopularity, he responded to it splendidly in 1821, when he said: ‘I am grown as popular in 1821 as I was unpopular formerly, and of the two unpopularity is the more convenient and gentlemanlike.’2
Then, in August 1822, Castlereagh committed suicide by cutting his throat. He had been complaining of overwork but both Castlereagh and the government had by 1822 reached a new popularity owing to the strong economic recovery. However, his minor nervous breakdown in 1801 suggests that, like many nervous people, he was badly affected by the removal of difficulties and stress.
Mrs Arbuthnot knew Castlereagh from 1811, before her marriage, and he was a close friend. He was in the habit of visiting her every couple of days at breakfast time to tell her about the debate the night before and liked to give her advice and a political education. According to her, he was not great at set speeches, having lacked the classical education of most politicians, but was very powerful in reply, when the ‘Opposition had been violent or ungentlemanlike’. She gives a lengthy description of Castlereagh’s last days, revealing that he showed signs of paranoia, talked of being blackmailed with accusations of a homosexual relationship, although he was ‘a great favourite among women’ having ‘retained all the personal beauty which had distinguished him in early youth’.3
 Percy Bysshe Shelley (1792-1822) Radical poet, now best known as the husband of the creator of ‘Frankenstein.’
 C. Litton Falkiner, Studies in Irish History and Biography, Mainly of the Eighteenth Century (London: Longmans, Green & Co., 1902) p. 178.
 Bamford and Wellington, The Journal of Mrs. Arbuthnot, 1820-32, Vol. 1, pp. 176-83.