Carl Philipp Gottfried von Clausewitz (1780 - 1831) was a Prussian General, influential military theorist, and disillusioned officer amongst those baffled by how Napoleon's army had changed the nature of war through his ability to motivate the populace and thus unleash war on a greater scale than was generally fought previously. He spent a considerable part of his life fighting against Napoleon and there is no doubt that the insight he gained from his experiences provided much of the raw material for the book. On War represents the compilation of his cogent observations. It is a book on military strategy and tactics written mostly after the Napoleonic wars, between 1816 and 1818, and published posthumously by his wife in 1832. It is one of the most important treatises on strategy ever written, and is prescribed at various military academies to this day.