Made Stabskapitän in 1790, Gneisenau served in Poland, 1793 - 1794. Subsequently to this, ten years of quiet garrison life in Jauer enabled him to undertake a wide range of military studies. In 1796 he married Caroline von Kottwitz. In 1806 he served as one of Hohenlohe's staff-officers, fought at Jena, and a little later commanded a provisional infantry brigade which fought under Lestocq in the Lithuanian campaign. Early in 1807 the Prussian Army sent Major von Gneisenau as commandant to Colberg, which, though small and ill-protected, succeeded in holding out until the Peace of Tilsit. The commandant received the much-prized order pour le mérite, and promotion to lieutenant-colonel.
A wider sphere of work now opened to him. As chief of engineers, and a member of the reorganizing committee, he played a great part, along with Scharnhorst, in the work of reconstructing the Prussian army. A colonel in 1809, he soon drew upon himself, by his energy, the suspicion of the dominant French, and Stein's fall (January 1809) was soon followed by Gneisenau's retirement. But, after visiting Russia, Sweden and England, he returned to Berlin and resumed his place as a leader of the patriotic party. In open military work and secret machinations his energy and patriotism were equally tested, and with the outbreak of the War of Liberation, Major-General Gneisenau became Blücher's quartermaster-general. Thus began the connection between these two soldiers which has furnished military history with its best example of the harmonious co-operation between the general and his chief-of-staff. With Blücher, Gneisenau served to the capture of Paris; his military character precisely complemented Blucher's, and under this happy guidance the young troops of Prussia, often defeated but never discouraged, fought their way into the heart of France. The plan of the march on Paris, which led directly to the fall of Napoleon, was specifically the work of the chief-of-staff. In reward for his distinguished service he was in 1814, - along with Yorck, Kleist and Bülow, made count at the same time as Blücher became prince of Wahlstatt; he also gained an annuity.
In 1815, once more chief of Blücher's staff, Gneisenau played a very conspicuous part in the Waterloo campaign. Senior generals, such as Yorck and Kleist, had been set aside in order that the chief-of-staff should have the command in case of need, and when on the field of Ligny the old field marshal was disabled, Gneisenau at once assumed the control of the Prussian army. Even in the light of the evidence that many years' research has collected, the precise part taken by Gneisenau in the events which followed is much debated. It is known that Gneisenau had the deepest distrust of the British commander, who, he considered, had left the Prussians in the lurch at Ligny, and that to the hour of victory he had grave doubts as to whether he ought not to fall back on the Rhine. Blücher, however, soon recovered from his injuries, and, with Grolmann, the quartermaster general, he managed to convince Gneisenau. The relations of the two may be illustrated by Brigadier-General Hardinge's report. Blücher burst into Hardinge's room at Wavre, saying Gneisenau has given way, and we are to march at once to your chief.
On the field of Waterloo, however, Gneisenau was quick to realise the magnitude of the victory, and he carried out the pursuit with a relentless vigour which has few parallels in history. In reward he gained further promotion and the insignia of the Black Eagle which bad been taken in Napoleon's coach. In 1816 he was appointed to command the VIlIth Prussian Corps, but soon retired from the service, both because of ill-health and for political reasons.
For two years he lived in retirement on his estate, Erdmannsdorf in Silesia, but in 1818 he became governor of Berlin in succession to Kalkreuth, and member of the Staatsrath (Council of State). In 1825 he became general field marshal. In 1831 he was appointed to the command of the Army of Observation on the Polish frontier, with Clausewitz as his chief-of-staff. At Posen he was struck down by cholera and died on 24 August 1831, soon followed by his chief-of-staff, who fell a victim to the same disease in November.
As a soldier, Gneisenau proved the greatest Prussian general since Frederick; as a man, his noble character and virtuous life secured him the affection and reverence, not only of his superiors and subordinates in the service, but of the whole Prussian nation. A statue by Rauch was erected in Berlin in 1855, and in memory of the siege of 1807 the Colberg grenadiers received his name in 1889. One of his sons led a brigade of the VIlIth Army Corps in the Franco-Prussian War in 1870.
See G. H. Pertz, Das Leben des Feldmarschalls Grafen Neitharth von Gneisenau, vols. 1-3 (Berlin, 1864 - 1869); vols. 4 and 5, G. Delbruck (lb. 1879, 1880), with numerous documents and letters; H. Delbruck, Das Leben des G. F. M. Grafen von Gneisenau (2 vols. 2nd ed,, Berlin, 1894), based on Pertz's work, but containing much new material; Frau von Beguelin, Denkwurdigkeiten (Berlin, 1892,); Hormayr, Lebensbilder aus den Befreiungskriegen (Jena, 1841); Pick, Aus dem brieflichen Nachlass Gneisenaus; also the histories of the campaigns of 1807 and 1813.
Original text from 1911 Encyclopaedia Britannica