These cordial ties were loosened, however, by the fresh crisis in the Eastern Question after 1838. Metternich was anxious to summon a European conference to Vienna, with a view to placing Turkey under a collective guarantee. Nicholas refused to be a party to it. Moreover, as Austria showed an inclination to ap proach the maritime powers, he determined to come to an agree ment with Great Britain, in order to settle the Eastern Question according to his own views ; this is the explanation of those con cessions in the Eastern Question which ended in the Quadruple Alliance of 184o and the humiliation of Louis Philippe's govern ment. The new Anglo-Russian entente led in 1844 to a visit of the tsar to the English court. (See EASTERN QUESTION.) When the storm of revolution burst over Europe in 1848, Nicholas remained entrenched behind the barriers of his own disci plined empire. But in 1849 he intervened in Hungary, at the en treaty of Francis Joseph, crushed the insurgent Hungarians and handed back their country as a free gift to the Habsburg king. Scarcely less valuable to Austria was the tsar's intervention in the quarrel between Austria and Prussia arising out of the Hesse inci dent and the general question of the hegemony of Germany. In October 185o he had a meeting with Francis Joseph at Warsaw, at which Count Brandenburg and Prince Schwarzenberg were pres ent. Prussia, he declared, must in the German question return to the basis of the treaties of 1815 and renew her entente with Austria; this was the only way of preserving the old friendship of Prussia and Russia. In face of the threat conveyed in this, the Prussian government decided to maintain peace (Nov. 2), Rado witz resigning as a protest. Thus Nicholas, who refused to believe in the perfidy ascribed by Frederick William to Austria, was the immediate cause of Prussia's humiliation at Olmiitz.
Nicholas was soon to have personal experience of the perfidy of Austria in the troubles that led up to the Crimean War. Grati tude, in the tsar's opinon, should have made her neutral if not friendly. When the dispute arose with Napoleon III. over the guardianship of the Holy Places Nicholas could not believe that Christian powers would resent his claim to protect the Chris tian subjects of the sultan; he believed he could count on the friendship of Austria and Prussia ; as for Great Britain, he would try to come to a frank understanding with her. The disillusion ment that followed was profound. In October 1853 Nicholas met his brother monarchs of the triple alliance at Warsaw for the last time. In December, at the conference of Vienna, Austria had
already passed over to the enemy. Prussia was wavering, neutral indeed, but joining the other powers in a guarantee of the in tegrity of Turkey (April 9, 1854), urging the tsar to accept the decisions of the Vienna conference, and on his refusal signing a defensive alliance with Austria (April 2o, which included among the casus belli the incorporation in Russia of the banks of the Danube and a Russian march on Constantinople. Thus Nich olas, the pillar of the European alliance, found himself isolated and at war, or potentially at war, with all Europe. The invasion of the Crimea followed, and with it a fresh revelation of the corruption and demoralization of the Russian system. At the outset Nicholas had grimly remarked that "Generals January and February" would prove his best allies. These acted, however, im partially; and if thousands of British and French soldiers perished of cold and disease in the trenches before Sevastopol, the tracks leading from the centre of Russia into the Crimea were marked by the bones of Russian dead. The revelation of his failure broke the spirit of the Iron Tsar, and on March 2, 1855, he threw away the life which a little ordinary care would have saved.
BIBLIOGRAPHY.-All other works on Nicholas I. were more or less superseded by Professor Theodor Schiemann's Geschichte Russlands unter Kaiser Nikolaus I., of which the 1st vol., Kaiser Alexander I. and die Ergebnisse seiner Lebensarbeit, was published at Berlin in 1904 ; the 2nd, carrying the history of Nicholas's reign down to the revolutions of 5830, in 1908. It is based on a large mass of unpublished material, and considerably modifies, e.g., the account of the accession of Nicholas and of the Dekabrist conspiracy given in chapter xiii. of vol. x. of the Cambridge Modern History, and tells for the first time the secret history of the Russo-Turkish War of 1828-29. The great Recueil des traites conclus par la Russie of T. T. de Martens (St. Petersburg, 5874-5909) contains admirable introductory essays, based on the unpublished Russian archives, and giving much material for the study of Nicholas's character and policy. Many documents are pub lished for the first time in Schiemann's work ; some, from the archives of Count Nesselrode, are published in the Lettres et papiers du Chancelier Comte de Nesselrode, t. vi. seq. For other works see bibliographies attached to the chapters on Russia in vol. x. and xi.