born Oct. 27, 1760, Schildau, near Torgau, Saxony
died Aug. 23, 1831, Posen, Prussia
Prussian field marshal and military reformer.
Along with Napoleon (1806) from a mercenary force into an instrument of modern warfare, introducing universal military service. In 1811–12 he traveled on secret missions to negotiate a new war against Napoleon, which was renewed in 1813. As chief of staff to {{link=Bl%C3%BCcher, Gebhard Leberecht von, prince von Wahlstatt">Gebhard von Blücher , he planned Prussian, and sometimes Russian, strategy. Gneisenau's insistence on the decisive battle and relentless pursuit proved successful at the Battle of Waterloo .