CLAUSEWITZ, KARL VON (178o-1831), Prussian gen eral and military writer, was born at Burg, near Magdeburg, on June 1, 1780. His family, originally Polish, had settled in Ger many at the end of the previous century. Entering the army in 1792, he first saw service in the Rhine campaigns of 1793-94, re ceiving his commission at the siege of Mainz. On his return to garrison duty he set to work so zealously to remedy the defects in his education caused by his father's poverty, that in I 8o r he was admitted to the Berlin academy for young officers, then directed by Scharnhorst. Scharnhorst, attracted by his pupil's in dustry and force of character, paid special attention to his train ing, and profoundly influenced the development of his mind. In 1803, on Scharnhorst's recommendation, Clausewitz was made "adjutant" (aide-de-camp) to Prince August, and he served in this capacity in the campaign of Jena (18o6), being captured along with the prince by the French at Prenzlau. A prisoner in France and Switzerland for the next two years, he returned to Prussia in 1809; and for the next three years, as a departmental chief in the ministry of war, as a teacher in the military school, and as military instructor to the crown prince, he assisted Scharn horst in the famous reorganization of the Prussian Army. In 1810 he married the countess Marie von Bruhl.
On the outbreak of the Russian war in 1812, Clausewitz, like many other Prussian officers, took service with his country's nominal enemy. This step he justified in a memorial, published for the first time in the Leben Gneisenaus by Pertz (1869) . At first adjutant to Gen. Phull, who had himself been a Prussian officer, he served later under Pahlen at Witepsk and Smolensk, and from the final Russian position at Kaluga he was sent to the army of Wittgenstein. It was Clausewitz who negotiated the convention of Tauroggen, which separated the cause of Yorck's Prussians from that of the French, and began the War of Liber ation (see YORCK VON WARTENBURG; also Blumenthal's Die Konvention von . Tauroggen, 1901) . As a Russian officer he superintended the formation of the Landwehr of east Prussia (see STEIN, H. F. K.), and in the campaign of 1813 he served as chief of staff to Count Wallmoden. He conducted the fight at Garde, and after the armistice, with Gneisenau's permission, published an account of the campaign (Der Feldzug von 1813 bis zum tiha ff enstillstand, Leipzig, 1813) . This work was long attributed to Gneisenau himself. After the peace of 1814 Clause witz re-entered the Prussian service, and in the Waterloo cam paign was present at Ligny and Wavre as Gen. Thielmann's chief of staff. This post he retained till 1818, when he was promoted major-general and appointed director of the Allgemeine Kriegs schule. Here he remained till in 1830 he was made chief of the 3rd Artillery Inspection at Breslau. Next year he became chief of staff to Field-marshal Gneisenau, who commanded an army of observation on the Polish frontier. After the dissolution of this army Clausewitz returned to his artillery duties; but on Nov. 18, 1831, he died at Breslau of cholera, which had proved fatal to his chief also, and a little previously, to his old Russian com mander Diebitsch on the other side of the frontier.
His collected works were edited and published by his widow, who was aided by some officers, personal friends of the general; in her task. Of the ten volumes of Hinterlassene Werke fiber Krieg and Krieg f uliruag (1832-37, later edition called Clause witz's Gesammte Werke, 1874) the first three contain Clause witz's masterpiece, Vom Kriege, an exposition of the philosophy of war. He produced no "system" of strategy, and his critics styled his work "negative" and asked "Qu'a-t-il f ovule?" What he had "founded" was that modern strategy which, by its hold on the Prussian mind, carried the Prussian arms to victory in 1866 and 1870, and his philosophy of war became, not only in Germany but in many other countries, the basis of military studies. But it has been argued since the World War that his teaching contributed to the deadlock and costly attrition strategy of 1914-18 through its excessive emphasis on purely military factors, a tendency naturally exaggerated by his disciples. The English and French translations (Graham, On War, 1873 ; Neu ens, La Guerre, 1849-52; or Vatry, Theorie de la grande guerre, 1899), with the German original, place the work at the disposal of students of most nationalities. The remaining volumes deal with military history: Vol. 4, the Italian campaign of 1796-97; vols. 5 and 6, the campaign of 1799 in Switzerland and Italy; vol. 7, the wars of 1813 to the armistice, and 1814; vol. 8, the Waterloo campaign; vols. 9 and io, papers on the cam paigns of Gustavus Adolphus, Turenne, Luxemburg, Munnich, John Sobieski, Frederick the Great, Ferdinand of Brunswick, etc. He also wrote fiber das Leben and den Charakter von Scharn horst (printed in Ranke's Historisch-politischer Zeitschri f t, 183 2) .
A manuscript on the catastrophe of 1806 long remained unpub lished. It was used by v. Hopfner in his history of that war, and eventually published by the Great General Staff in 1888 (French translation, 1903) . Letters from Clausewitz to his wife were published in Zeitschri f t f fir preussische Landeskunde (5876). See von Meerheimb, Karl von Clausewitz (1875), also Memoir in Allgemeine deutsche Biographie; Schwartz, Leben des General von Clausewitz and der Frau Marie von Clausewitz (2 vols., ; Bernhardi, Leben des Generals von Clausewitz (loth Supplement, Militdr. Wochenblatt, 1878) .
