Robert Stewart, Viscount Castlereagh

British politician (1769–1822)

Robert Stewart, 2nd Marquess of Londonderry (18 June 176912 August 1822), usually known as Lord Castlereagh, derived from the courtesy title Viscount Castlereagh, by which he was styled from 1796 to 1821, was an Anglo-Irish politician and statesman. As secretary to the Viceroy of Ireland, he worked to suppress the Rebellion of 1798 and to secure passage in 1800 of the Irish Act of Union. As the Foreign Secretary of the United Kingdom from 1812, he was central to the management of the coalition that defeated Napoleon, and was British plenipotentiary at the Congress of Vienna. In the post-war government of Lord Liverpool, Castlereagh was seen to support harsh measures against agitation for reform. He killed himself while in office in 1822.




  • It is not insurrection we now want in Italy, or elsewhere—we want disciplined force, under Sovereigns we can trust.
    • Letter to Lord William Bentinck (3 April 1814), quoted in Correspondence, Despatches, and Other Papers, of Viscount Castlereagh, Second Marquess of Londonderry. Third Series. Military and Diplomatic. Vol. IX., ed. Charles William Vane, Marquess of Londonderry (1852), p. 434
  • I still feel great doubts about the acquisition in sovereignty of so many Dutch colonies. I am sure our reputation on the Continent, as a feature of strength, power, and confidence, is of more real moment to us than an acquisition thus made. The British merchants ought to be satisfied, if we secure them a direct import.
    • Letter to Lord Liverpool (19 April 1814), quoted in Correspondence, Despatches, and Other Papers, of Viscount Castlereagh, Second Marquess of Londonderry. Third Series. Military and Diplomatic. Vol. IX., ed. Charles William Vane, Marquess of Londonderry (1852), pp. 474-475
  • It is impossible not to perceive a great moral change coming on in Europe, and that the principles of freedom are in full operation. The danger is, that the transition may be too sudden to ripen into anything likely to make the world better or happier. We have new constitutions launched in France, Spain, Holland, and Sicily. Let us see the result before we encourage farther attempts. The attempts may be made, and we must abide the consequences; but I am sure it is better to retard than accelerate the operation of this most hazardous principle which is abroad.
    • Letter to Lord William Bentinck (7 May 1814), quoted in Correspondence, Despatches, and Other Papers, of Viscount Castlereagh, Second Marquess of Londonderry. Third Series. Military and Diplomatic. Vol. II., ed. Charles William Vane, Marquess of Londonderry (1853), p. 18
  • These arguments about natural defences and strategic boundaries are pushed too far. Real defence and security comes from the guarantee which is given by the fact that they cannot touch you without declaring war on all those interested in maintaining things as they are.
    • Remarks to the representative of Geneva, Charles Pictet de Rochemont, who opposed the French claim to the Pays de Gex (May 1814), quoted in C. K. Webster, The Foreign Policy of Castlereagh 1812–1815: Britain and the Reconstruction of Europe (1931), p. 268
  • If we are to undertake the job, we must leave nothing to chance. It must be done upon the largest scale... [Y]ou must inundate France with force in all directions. If Bonaparte could turn the tide, there is no calculating upon his plan; and we must always recollect that Poland, Saxony, and much Jacobinism, are in our rear.
    • Letter to the Duke of Wellington (26 March 1815), quoted in Correspondence, Despatches, and Other Papers, of Viscount Castlereagh, Second Marquess of Londonderry. Vol. X., ed. Charles William Vane, Marquess of Londonderry (1853), pp. 285-286
  • You will fully appreciate the Parliamentary importance of not having imputed to us that Louis XVIII., by being made an Ally against Buonaparte, has been made master of the confederacy for his own restoration. His Majesty cannot wish us to feel more decisively the importance of his restoration than we do; and most assuredly every effort will be made so to conduct the war so as to lead to this result, but we cannot make it a sine qua non. Foreign Powers may justly covenant for the destruction of Buonaparte's authority as inconsistent with their own safety, but it is another question avowedly to stipulate as to his successor. This is a Parliamentary delicacy.
    • Letter to Lord Clancarty (8 April 1815), quoted in Correspondence, Despatches, and Other Papers, of Viscount Castlereagh, Second Marquess of Londonderry. Vol. X., ed. Charles William Vane, Marquess of Londonderry (1853), p. 301
  • I hope you will be able to make M. de Blacas and those about the king understand, that John Bull fights best, when he is not tied, and that, altho' as a line of policy we can with good management connect the support of the Bourbons with the avowed object of the war, we never could sustain as a principle, that we were committed irrevocably to His Majesty to make this a sine qua non under every possible circumstance. Such an engagement would defeat its own purpose by rendering that questionable, which if done voluntarily, would command a general concurrence.
    • Letter to Sir Charles Stuart (19 April 1815), quoted in C. K. Webster, The Foreign Policy of Castlereagh 1812–1815: Britain and the Reconstruction of Europe (1931), p. 545
  • The steadiness of this country in the war will depend upon our making it clear that the Continent has voluntarily decided to seek its safety in arming.
    • Letter to Sir Charles Stuart (19 April 1815), quoted in C. K. Webster, The Foreign Policy of Castlereagh 1812–1815: Britain and the Reconstruction of Europe (1931), p. 545
  • Fouché and men of his stamp are nowhere so little to be dreaded as in office, mixed up with other materials. Tyrants may poison or murder an obnoxious character, but the surest and only means a constitutional sovereign has to restrain such a character is to employ him. Office soon strips him of his most dangerous adherents—he comes unpopular, he can be laid aside at pleasure, and sinks to his true lead. So far from making himself visibly responsible for everything, the King ought to throw upon his Ministers the odium and risk of conducting his service. His Majesty ought to turn the political control towards the Minister for the time being and not entertain it himself beyond affording him the due support which his services may deserve. This is the true strength of a constitutional king. All paper constitutions are of comparatively small importance; the essence of a free state is so to manage the party warfare, as to reconcile it with the safety of the sovereign—to do this, the King must give the contending parties facilities against each other, and not embark himself too deeply with any.
    • Letter to Louis XVIII of France (8 May 1815), quoted in C. K. Webster, The Foreign Policy of Castlereagh 1812–1815: Britain and the Reconstruction of Europe (1931), pp. 546-547
  • I much suspect neither Austria nor Prussia, and certainly none of the smaller Powers, have any sincere desire to bring the present state of things to a speedy termination: so long as they can feed, clothe, and pay their armies at the expense of France, and put English subsidies into their pockets besides, which nothing can deprive them of, previous to the 1st of April, 1816, but the actual conclusion of a treaty with France, you cannot suppose they will be in a great hurry to come to a final settlement, since the war may be said to have closed.
    • Letter to Lord Liverpool (17 August 1815), quoted in Correspondence, Despatches, and Other Papers, of Viscount Castlereagh, Second Marquess of Londonderry. Vol. X., ed. Charles William Vane, Marquess of Londonderry (1853), p. 485
  • No doubt, the prevailing sentiment throughout Germany is in favour of territorially reducing France. After all the people have suffered, and with the ordinary inducements of some fresh acquisitions, it is not wonderful that it should be so; but it is one thing to wish the thing done, and another to maintain it when done; and, in calculating the chances of the latter, we ought to be aware that none of these Powers can, for any time, keep up war establishments, or, having once laid them down, find the means of speedily resuming them; and that, if the course adopted materially increases the chances of early war with France, these acquisitions may be of short duration, whilst our chances of an interval of peace will be diminished, and we may be obliged, in order to keep France within any bounds, to take the weight of the war, in a pecuniary sense, upon ourselves.
    • Letter to Lord Liverpool (17 August 1815), quoted in Correspondence, Despatches, and Other Papers, of Viscount Castlereagh, Second Marquess of Londonderry. Vol. X., ed. Charles William Vane, Marquess of Londonderry (1853), p. 488
  • My belief and hope, then, is, if the arrangement is made with some attention to the feelings and interests of the country, that the King, his Government, and the loyal party in France, will ally themselves with you; and that, thus sustained, the King will be able gradually to establish his authority, which, if accomplished, is valuable beyond all other securities we can acquire. If he fails, we shall not have to reproach ourselves with having precipitated his fall, and we shall have full time to take our precautions. If, on the contrary, we push things now to an extremity, we leave the King no resource in the eyes of his own people but to disavow us; and, once committed against us in sentiment, he will be obliged soon either to lead the nation into war himself, or possibly be set aside to make way for some more bold and enterprising competitor. The whole of this view of the question turns upon a conviction that the King's cause in France is far from hopeless, if well conducted, and that the European alliance can be made powerfully instrumental to his support, if our securities are framed in such a manner as not to be ultimately hostile to France, after she shall have given protracted proofs of having ceased to be a revolutionary State.
    • Letter to Lord Liverpool (17 August 1815), quoted in Correspondence, Despatches, and Other Papers, of Viscount Castlereagh, Second Marquess of Londonderry. Vol. X., ed. Charles William Vane, Marquess of Londonderry (1853), p. 489
  • I have no doubt the middle line would be the most popular, and that, in extorting the permanent cession of one or two fortresses of great name, our labours would carry with them an éclat which is not likely to attend them, according to the course we recommend. But it is not our business to collect trophies, but to try if we can bring back the world to peaceful habits. I do not believe this to be compatible with any attempt now materially and permanently to affect the territorial character of France, as settled by the Peace of Paris; neither do I think it a clear case (if we can, by imposing a strait waistcoat upon that Power for a number of years, restore her to ordinary habits, and weighing the extraordinary growth of other States in latter times, and especially of Russia) that France, even with her existing dimensions, may not be found a useful rather than a dangerous member of the European system.
    • Letter to Lord Liverpool (17 August 1815), quoted in Correspondence, Despatches, and Other Papers, of Viscount Castlereagh, Second Marquess of Londonderry. Vol. X., ed. Charles William Vane, Marquess of Londonderry (1853), pp. 490-491
  • I feel no wrath against the people. I am only doing my duty.

Dispatch to Lord Cathcart (18 September 1813)

Dispatch to the British Ambassador to Russia, Lord Cathcart. Printed in C. K. Webster (ed.), British Diplomacy 1813–1815: Select Documents Dealing With the Reconstruction of Europe (1921)
  • The present Confederacy may be considered as the union of nearly the whole of Europe against the unbounded and faithless ambition of an individual [Napoleon]. It comprehends not only all the great monarchies, but a great proportion of the secondary Powers. It is not more distinguished from former Confederacies against France by the number and magnitude of the Powers engaged than by the national character which the war has assumed throughout the respective states. On former occasions it was a contest of sovereigns, in some instances perhaps, against the prevailing sentiment of their subjects; it is now a struggle dictated by the feelings of the people of all ranks as well as by the necessity of the case. The sovereigns of Europe have at last confederated together for their common safety, having in vain sought that safety in detached and insulated compromises with the enemy. They have successively found that no extent of submission could procure for them either safety or repose, and that they no sooner ceased to be objects of hostility themselves, than they were compelled to become instruments in the hands of France for effectuating the conquest of other unoffending states. The present Confederacy may therefore be pronounced to originate in higher motives and to rest upon more solid principles than any of those that have preceded it, and the several Powers to be bound together for the first time by one paramount consideration of an imminent and common danger.
    • pp. 19-20
  • It is this common danger which ought always to be kept in view as the true basis of the alliance, and which ought to preclude defection from the common cause. It must be represented to the Allies that having determined to deliver themselves from the vengeance of the conqueror by their collective strength, if collectively they fail, they are separately lost. He never will again trust any one of them with the means of self-defence—their only rational policy then is inseparable union—to make the contest that of their respective nations, to persevere under every disaster, and to be satisfied that to end the contest safely the enemy must be compelled to treat with them collectively, whilst the best chance of an early peace is at once to satisfy the enemy that a separate negotiation is unattainable.
    • p. 20
  • As opposed to France, a peace concluded in concert, though less advantageous in its terms, would be preferable to the largest concessions received from the enemy as the price of disunion. The great object of the Allies, whether in war or negotiation, should be to keep together, and to drive back and confine the armies of France within the circle of their own immediate resources. This alone can bring down the military force of the enemy to its natural level, and save Europe from being progressively conquered with its own spoils.
    • p. 20
  • To suppose that the Powers on the side of Germany might be induced to sign a peace, leaving Great Britain and the nations of the Peninsula to carry on the war, or that the enemy being expelled from the Peninsula, Spain might sheath the sword, leaving the Continental Powers to sustain the undivided shock of French power, is to impute to them all a total blindness to their common safety. Were either of these interests to attempt to shelter themselves in a separate peace, it must leave France master of the fate of the other, and ultimately of both. It is by the war in Spain that Russia has been preserved, and that Germany may be delivered; it is by the war in Germany that Spain may look to escape the subjugation that otherwise ultimately await her. So long as both manfully contend in the field against France, neither can be absolutely overwhelmed, and both, upon every sound principle of military calculation, must by perseverance triumph. To determine to stand or fall together is their only safety, and to effect this the confederates must be brought to agree to certain fixed principles of common interest.
    • pp. 20-21

Speech in the House of Commons (15 March 1815)

Address Respecting the Congress of Vienna, HC Deb 20 March 1815 vol 30
  • He had now the satisfaction to say, that although he was unable to announce the immediate and actual abolition of the [slave] trade, all the Powers of Europe had agreed that it should not be extended beyond the period at which by possibility it could be terminated. They had concurred in a solemn address to the world, on the necessity of sweeping a trade, so intolerable in a moral point of view, from the face of the earth, and had pledged themselves to take no further time for that purpose than was necessary for the internal regulation of their own dominions.
  • It was no small gratification to him to have brought the different Powers of Europe, not only to an agreement to the principle of the abolition [of the slave trade], but to an early and absolute accomplishment of it. He heartily wished that he could announce that this curse of humanity had ceased to exist, but final sentence had been passed upon it.
  • The question which the House would have to decide was, whether a system had been created under which all countries might live in that peace which it was the great object of the confederacy to establish. A difference of sentiment on some points of the arrangements could be no impeachment of the wisdom of the whole. Perfection belonged to no work of human beings, even when many years were devoted to it; much less when its completion was accelerated by the necessity of circumstances. On this general principle he applauded and was prepared to maintain the proceedings of the Congress at Vienna.
  • The Allies had made war, not for the sake of subjugating any power, but for the sake of preserving the whole of Europe from subjugation; they had succeeded in their object; and they had endeavoured to give to the different powers of the European commonwealth a protection from that danger by which they had already been destroyed.
  • If Buonaparté succeeded in re-establishing his authority in France, peace must be despaired of; at least such a peace as we had recently the hope of enjoying. The question now was, whether Europe must once more return to that dreadful system which it had so long pursued; whether Europe was again to become a series of armed nations, and whether Great Britain among them was to abandon that wholesome state into which she was now settling, to resume her station as a military people, and again to struggle for the independence of the world? These were questions of no small magnitude, depending upon events now in issue, depending upon a new and an unexpected contest, in which the liberties of mankind were once more assaulted and endangered.
  • It was not merely a question whether the Bourbon family, which had already given so many benefits to France, and among them, that best of all benefits, peace, should continue to reign in France, but whether tyranny and despotism should again reign over the independent nations of the continent? Whether as applied to this country, we should enjoy the happy state that we had bought with our blood after a long struggle, or whether we should once more revert to that artificial system which, during that struggle, we were compelled to maintain? Upon these points there could exist only one feeling, and his lordship trusted that Providence would ordain only one result.


  • The system of the Emperor [of Russia] did him honour as a monarch and as a man. Nothing could be more pure than the ends which he had set before himself in all his actions; but this system aims at a perfection, which we do not believe applicable to this century or to mankind. We cannot follow him along this path. It is a vain hope, a beautiful phantom, which England above all can not pursue. All speculative policy is outside her powers. It is proposed now to overcome the revolution; but so long as this revolution does not appear in more distinct shape, so long as this general principle is only translated into events like those of Spain, Naples and Portugal—which, strictly speaking, are only reforms, or at the most domestic upsets, and do not attack materially any other State—England is not ready to combat it. Upon any other question purely political, she would always deliberate and act in the same way as all the other Cabinets.
    • Remarks to Christoph von Lieven during the Congress of Troppau (October 1820), quoted in C. K. Webster, The Foreign Policy of Castlereagh 1815–1822: Britain and the European Alliance (1925), pp. 282-283

State Paper (5 May 1820)

Written in response to the military revolt in Spain. Printed in Adolphus William Ward and George Peabody Gooch (eds.), The Cambridge History of British Foreign Policy, 1783–1919. Volume 2: 1815–1866 (1923)
  • In this Alliance, as in all other human Arrangements, nothing is more likely to impair, or even to destroy its real utility, than any attempt to push its duties and its obligations beyond the Sphere which its original conception and understood Principles will warrant.—It was an Union for the re-conquest and liberation of a great proportion of the Continent of Europe from the military domination of France; and having subdued the Conqueror, it took the State of Possession, as established by the Peace, under the protection of the Alliance.—It never was, however, intended as an Union for the Government of the World, or for the Superintendence of the Internal Affairs of other States.
    • pp. 626-627
  • It provided specifically against an infraction on the part of France of the state of possession then created: It provided against the Return of the Usurper or any of his Family to the throne: It further designated the Revolutionary Power which had convulsed France and desolated Europe, as an object of it's constant solicitude, but it was the Revolutionary power more particularly in its Military Character actual and existent within France against which it intended to take Precautions, rather than against the Democratic Principles, then as now, but too generally spread throughout Europe.
    • p. 627
  • In thus attempting to limit the objects of the Alliance within their legitimate Boundary, it is not meant to discourage the utmost frankness of communication between the Allied Cabinets; their Confidential Intercourse upon all Matters, however foreign to the Purposes of the Alliance, is in itself a valuable expedient for keeping the current of sentiment in Europe as equable and as uniform as may be... but what is intended to be combated as forming any part of their Duty as Allies, is the Notion, but too perceptibly prevalent, that whenever any great Political Event shall occur, as in Spain, pregnant perhaps with future Danger, it is to be regarded almost as a matter of course, that it belongs to the Allies to charge themselves collectively with the Responsibility of exercising some Jurisdiction concerning such possible eventual Danger. One objection to this view of our Duties, if there was no other, is, that unless We are prepared to support out interference with force, our judgment or advice is likely to be but rarely listened to, and would by frequent Repetition soon fall into complete contempt. So long as We keep to the great and simple conservative principles of the Alliance, when the Dangers therein contemplated shall be visibly realised, there is little risk of difference or of disunion amongst the Allies.
    • p. 627
  • We may all agree that nothing can be more lamentable, or of more dangerous example, than the late revolt of the Spanish Army: We may all agree that nothing can be more unlike a monarchical Government, or less suited to the wants and true interests of the Spanish nation, than the Constitution of the year 1812; We may also agree, with shades of difference, that the consequence of this state of things in Spain may eventually bring danger home to all our own doors, but it does not follow, that We have therefore equal means of acting upon this opinion.
    • pp. 627-628
  • In this country at all times, but especially at the present conjuncture, when the whole Energy of the State is required to unite reasonable men in defence of our existing Institutions, and to put down the spirit of Treason and Disaffection which in certain of the Manufacturing Districts in particular, pervades the lower orders, it is of the greatest moment, that the public sentiment should not be distracted or divided, by any unnecessary interference of the Government in events, passing abroad, over which they can have none, or at best but very imperfect means of controul.
    • pp. 628-629
  • Great Britain has perhaps equal Power with any other State to oppose Herself to a practical and intelligible Danger, capable of being brought home to the National Feeling:—When the Territorial Balance of Europe is disturbed, she can interfere with effect, but She is the last Govt. in Europe, which can be expected, or can venture to commit Herself on any Question of an abstract character.
    • p. 632
  • We shall be found in our Place when actual danger menaces the System of Europe; but this Country cannot, and will not, act upon abstract and speculative Principles of Precaution.
    • p. 632

Dispatch to Sir Charles Bagot (28 October 1821)

Dispatch to the British Ambassador to Russia, Sir Charles Bagot, in response to the Greek War of Independence. Printed in C. K. Webster, The Foreign Policy of Castlereagh 1815–1822: Britain and the European Alliance (1925)
  • It will naturally occur to every virtuous and generous mind, and to none more probably than to the Emperor of Russia's own,—indeed it is the first impression which presents itself to every reflecting observer when he contemplates the internal state of European Turkey—viz. : Is it fit that such a state of things should continue to exist? Ought the Turkish yoke to be for ever rivetted upon the necks of their suffering and Christian subjects; and shall the descendants of those, in admiration of whom we have been educated, be doomed in this fine country to drag out, for all time to come, the miserable existence to which circumstances have reduced them?
    • p. 376
  • It is impossible not to feel the appeal; and if a statesman were permitted to regulate his conduct by the counsels of his heart instead of the dictates of his understanding, I really see no limits to the impulse, which might be given to his conduct, upon a case so stated. But we must always recollect that his is the grave task of providing for the peace and security of those interests immediately committed to his care; that he must not endanger the fate of the present generation in a speculative endeavour to improve the lot of that which is to come.
    • pp. 376-377
  • I cannot, therefore, reconcile it to my sense of duty to embark in a scheme for new modelling the position of the Greek population in those countries at the hazard of all the destructive confusion and disunion which such an attempt may lead to, not only within Turkey but in Europe. I am by no means persuaded, were the Turks even miraculously to be withdrawn (what it would cost of blood and suffering forcibly to expel them I now dismiss from my calculations) that the Greek population, as it now subsists or is likely to subsist for a course of years, could frame from their own materials a system of government less defective either in its external or internal character, and especially as the question regards Russia, than that which at present unfortunately exists. I cannot, therefore, be tempted, nor even called upon in moral duty under loose notions of humanity and amendment, to forget the obligations of existing Treaties, to endanger the frame of long established relations, and to aid the insurrectionary efforts now in progress in Greece, upon the chance that it may, through war, mould itself into some scheme of government, but at the certainty that it must in the meantime, open a field for every ardent adventurer and political fanatic in Europe to hazard not only his own fortune, but what is our province more anxiously to watch over, the fortune and destiny of that system to the conservation of which our latest solemn transactions with our Allies have bound us.
    • p. 377

Quotes about Castlereagh

  • On the sad day following that of his death, one of his servants was asked whether he had remarked any change in him; the answer was 'Yes;' and being further asked to state the nature of the change, he replied, 'One day he spoke sharply to me!'
    • Countess Brownlow, Slight Reminiscences of a Septuagenarian from 1802 to 1815 (1868), p. 198
  • Put all their other men together in one scale, and poor Castlereagh in the other—single, he plainly weighed them down... One can't help feeling a little for him, after being pitted against him for several years pretty regularly. It is like losing a connection suddenly. Also, he was a gentleman, and the only one amongst them.
    • Henry Brougham to Thomas Creevey (19 August 1822), quoted in Herbert Maxwell (ed.), The Creevey Papers: A Selection from the Correspondence & Diaries of the late Thomas Creevey, M.P. Vol. II (1905), p. 44
  • It is not, however, by one or two isolated successes that Lord Castlereagh's foreign policy ought to be tried. It is best judged by its general results. During the war his aim was to overthrow Napoleon, and to reduce France within her ancient limits. After the war his aim was to uphold the balance of power, and so to secure lasting peace to Europe. When the direction of England's foreign policy passed from his hands, both objects had been attained... For forty years the peace of Europe flourished undisturbed by one single conflict between any of the five great Powers who adjusted their differences at Vienna... Europe has not enjoyed so long a repose from the curse of war since the fall of the Roman empire. Such an achievement is an ample justification of the acts of the Congress of Vienna and of the minister who bore so large a part in shaping its decrees.
    • Lord Robert Cecil, 'Lord Castlereagh', Quarterly Review (January 1862), quoted in Essays by the late Marquess of Salisbury K.G. Biographical (1905), p. 23
  • It was a mere calumny to call him an enemy to freedom. In its truest and most literal sense—the exemption from oppression—he did more for it than any statesman of his age. We have the testimony of the Duke of Wellington, that he had done more to destroy the slave-trade than any man in Europe; and the struggle which absorbed the best years of his life was a struggle on a vast scale for the liberties of mankind.
    • Lord Robert Cecil, 'Lord Castlereagh', Quarterly Review (January 1862), quoted in Essays by the late Marquess of Salisbury K.G. Biographical (1905), pp. 55–56
  • [F]rom Napoleon's tyranny time gave no respite, and insignificance no escape. His exactions ground down every income, and his massacres, thinly disguised under military names, thinned every village, from Reggio to Lilbeck. To have borne a large part in freeing Europe from such a scourge as this—to have provided securities that made it for the future an impossibility—was to have done a greater service to the cause of freedom than any shifting of the equilibrium of electoral power is ever likely to effect.
    • Lord Robert Cecil, 'Lord Castlereagh', Quarterly Review (January 1862), quoted in Essays by the late Marquess of Salisbury K.G. Biographical (1905), p. 56
  • Most sincerely do I congratulate you; and be assured that the fullest justice is done to the great abilities you have displayed through the whole of the transactions which you have so successfully and wonderfully managed. Your superiority and authority are now fixed.
    • Edward Cooke to Castlereagh (9 April 1814), quoted in Correspondence, Despatches, and Other Papers, of Viscount Castlereagh, Second Marquess of Londonderry. Third Series. Military and Diplomatic. Vol. IX., ed. William Vane, Marquess of Londonderry (1852), p. 454
  • As for my friend Lord Castlereagh, he is so cold that nothing can warm him.
  • As a Minister he is a great loss to his party, and still greater to his friends and dependants, to whom he was the best of patrons; to the country I think he is none. Nobody can deny that his talents were great, and perhaps he owed his influence and authority as much to his character as to his abilities. His appearance was dignified and imposing; he was affable in his manners and agreeable in society. The great feature of his character was a cool and determined courage, which gave an appearance of resolution and confidence to all his actions, and inspired his friends with admiration and excessive devotion to him, and caused him to be respected by his most violent opponents. As a speaker he was prolix, monotonous, and never eloquent, except, perhaps, for a few minutes when provoked into a passion by something which had fallen out in debate... He never spoke ill; his speeches were continually replete with good sense and strong argument, and though they seldom offered much to admire, they generally contained a great deal to be answered. I believe he was considered one of the best managers of the House of Commons who ever sat in it, and he was eminently possessed of the good taste, good-humor, and agreeable manners which are more requisite to make a good leader than eloquence, however brilliant.
    • Charles Greville, diary entry (13 August 1822), quoted in Henry Reeve (ed.), The Greville Memoirs: A Journal of the Reigns of King George IV. and King William IV. by the late Charles C. F. Greville, Vol. I (1875), pp. 52–53
  • [I]t was this man, more than any other, who forged again a European connection for Britain, who maintained the Coalition, and negotiated the settlement which in its main outlines was to last for over fifty years. Psychologists may well ponder how it came about that this Irish peer, whose career had given no indication of profound conceptions, should become the most European of British statesmen. No man more different from his great protagonist, Metternich, could be imagined. Metternich was elegant, facile, rationalist; Castlereagh, solid, ponderous, pragmatic; the former was witty and eloquent, if somewhat pedantic; the latter cumbersome in expression, although effective in debate; Metternich was doctrinaire and devious; Castlereagh, matter-of-fact and direct. Few individuals have left behind them such a paucity of personal reminiscences. Icy and reserved, Castlereagh walked his solitary path, as humanly unapproachable as his policy came to be incomprehensible to the majority of his countrymen. It was said of him that he was like a splendid summit of polished frost, icy, beautiful, aloof, of a stature that nobody could reach and few would care to.
  • There was one at Paris, however, who for a brief three months represented the conscience of Europe. It is difficult to explain why it should have been Castlereagh who resisted the Prussian clamour for the dismemberment of France in which even Metternich joined to the extent of demanding the permanent dismantling of the outer belt of French fortifications. Or why he should have refused always in such periods to go along with the Cabinet and Parliament, both urging a punitive peace. Yet France was spared and the equilibrium of Europe saved by the representative of the insular power which stood in least danger from immediate attack. At no other time in his career did Castlereagh show to greater advantage than in his battle for the equilibrium at Paris. Misunderstood at home, without the support of the moral framework which Metternich had provided in previous frays, he conducted himself with his customary methodical reserve, cumbersomely persuasive, motivated by an instinct always surer than his capacity for expression. This was the man on whom Europe for two generations heaped opprobrium as the destroyer of its liberties, because so much had the political equilibrium come to be taken for granted that the social contest overshadowed all else; to the extent that it was forgotten that without the political structure so resolutely preserved by Castlereagh, there would have been no social substance left to contend for.
  • His character will not be very easily defined in the page of history in which it must stand so conspicuously from the great events with which it has been connected. No man certainly ever traded so largely on so small a capital, but presence of mind, some sagacity, a good temper and good manners supplied the place of knowledge and eloquence.
  • I cannot praise Castlereagh enough. His attitude is excellent and his work as direct as it is correct. I cannot find a single point of difference with him and assure you that his mood is peaceful, peaceful in our sense.
    • Klemens von Metternich, report quoted in Henry Kissinger, A World Restored: Metternich, Castlereagh and the Problems of Peace 1812–1822 (1957; 1973), pp. 114-115
  • It is a great misfortune. The man is irreplaceable, especially for me... Castlereagh was the only person in his country who had experience in foreign affairs.
  • Quest.—Why is a Pump like Viscount Castlereagh?
    Answ.—Because it is a slender thing of wood,
    That up and down its awkward arm doth sway,
    And coolly spout, and spout, and spout away,
    In one weak, washy, everlasting flood!
  • Mackintosh used to say of Castlereagh that he had all the inferior qualities of a leader in an extraordinary degree. Though his language was often ungrammatical, his metaphors and figures so strangely perplexed and confused as to set the House a laughing, yet I have heard him speak in such a powerful, impressive and eloquent style as would have done honour to any man. The more he was pressed...the better he spoke, both in matter and manner. He was a handsome, fine looking man, good natured, high bred, and his courage was so undoubted that he could allow people to take liberties with him, or disregard them, as unworthy of his notice, which other men might have lost reputation by not resenting.
  • Castlereagh, who had been often pointed out as the successor of Pitt, wanted the large views of that great man... [He] was an obscure orator, garnishing his speeches with confused metaphors... He had no classical quotations, no happy illustration, no historical examples... Yet his influence with his party was very great, and he was, till near the close of his life, a successful leader of the House of Commons. For this end he possessed...very considerable advantages. He was, as a man of business, clear, diligent, and decided. His temper was admirable – bold and calm, good humoured and dispassionate. He was a thorough gentleman; courteous, jealous of his own honour, but full of regard for the feelings of others. No one doubted his personal integrity, however much they might dislike his policy.
  • There probably never was a statesman whose ideas were so right and whose attitude to public opinion was so wrong. Such disparity between the grasp of ends and the understanding of means amounts to a failure in statesmanship.