On War is a book on war and military strategy by Prussian general Carl von Clausewitz (1780-1831), written mostly after the Napoleonic wars, between 1816 and 1830, and published posthumously by his wife Marie von Bruhl in 1832. His 10-volume collected works contain most of his larger historical and theoretical writings, though not his shorter articles and papers or his extensive correspondence with important political, military, intellectual and cultural leaders in the Prussian state. On War is formed by the first three volumes and represents his theoretical explorations. It is one of the most important treatises on political-military analysis and strategy ever written, and remains both controversial and an influence on strategic thinking."