The Art of War (1521) is the only one of Machiavellis major works to be published during his lifetime, and the one which he doubtless believed to be his most important. In it, Machiavelli made liberal use of the theories of the Romans while advancing the revolutionary idea that politics and war constitute a kind of functional unity. }In medieval warfare, organization, staff services, hierarchy of command, and codes of military law were nonexistent. Machiavelli changed all that. For him, discipline was of supreme importance. War is war, he believed, a no-holds-barred contest, and victory the supreme aim to which all other considerations must be subordinated. To this end, Machiavelli instituted the systematic conception of troop formation, which until then had been almost unheard-of. The Art of War was widely read and highly esteemed throughout the sixteenth century. It was one of the favorite books of Frederick the Great; Napoleon, Saint-Cyr, and Clausewitz all held it in very high regard. Like The Prince and The Discourses , it is vividly and concisely written. But most importantly, The Art of War outlines most of the fundamental questions that theorists of war continue to examine today, making it essential reading for any student of military history, strategy, or theory. }