Carl Von Clausewitz (1780-1831) was a professional soldier from the age of 12 to his death from Cholera a disease he incurred on active duty at the age of 51. He first saw combat in 1794 when he was 13. He experienced first-hand Prussia’s disastrous military humiliation by Napoleon in 1806, was captured, and returned to Prussia a passionate military reformer. As a junior staff officer, he worked closely with the great Prussian military reformers Gerhard Von Scharnhorst (who was his mentor) and August Von Gneisenau (who became his friend and protector). In 1810, he was appointed military tutor to the crown prince, for whom he wrote (in 1812) a military treatise we call The Principles of War. The same year, on a matter of high principle, he gave up his commission and joined the Russian army to fight Napoleon. He fought throughout the Russian campaign and on through the Wars of Liberation of 1813 and 1814. He was Prussian III Corps chief of staff during the campaign of 1815. It was Clausewitz’s corps which outnumbered two to coe held Grouchy’s forces at Wavre, contributing decisively to Napoleon’s defeat at Waterloo.
Clausewitz had a reputation in the Prussian army as both an idealist and a superb staff officer, but he was considered temperamentally unsuitable for command. No hint of personal scandal attaches to Clausewitz, and his intellectual integrity was the driving force behind the ruthless examination of military-theoretical ideas that we find in his greatest book, On War. However, while he rose very high in the King’s service, he was widely considered too open to liberal ideas to be altogether politically reliable. His ideas on war are heavily influenced by the mass popular warfare of the French Revolutionary period, and those ideas were uncomfortable to conservative aristocrats.
Clausewitz’s relationship to Napoleon is often misunderstood. Although he is often called the “high-priest of Napoleon” (Liddell Hart’s and J.F.C. Fuller’s term for him), it is important to note that, in fact, Clausewitz represents not the ideas of Napoleon but rather those of his most capable opponent, the Prussian military reformer Gerhard Von Scharnhorst.