Frederick II’s renown was based above all on his ability as a military leader. In Clausewitz’s great work On War (1827) he appears alongside Julius Caesar, Gustavus Adolphus, and Charles XII exclusively as a soldier and commander. That this was only one dimension of a multifaceted personality, whose contradictory whole was made up of quite disparate elements, is often overlooked. Frederick’s military role can only be understood in terms of the way he united in his own person war and politics, military and philosophical intelligence, and an ability for both practical action and theoretical reflection. In the vision the King himself had of a good military leader, these prerequisites always were inextricably bound together. ‘Whoever believes that a general needs only courage, is very wrong’, he wrote in 1770 in the Principles of Military Camps and Tactics. ‘Courage is of course an important quality, but he has to possess other abilities. A general determined to preserve order and discipline among his troops deserves praise, but this would not suffice at a time of war because in everything he does he needs good judgement. How can he attain this, however, if he lacks knowledge and ability?’ According to Frederick, this resulted from historical developments. Since the invention of gunpowder, the system of mutual destruction had completely changed and war had assumed a totally different form. ‘Force of numbers, the mainstay of the heroes of old, no longer counts. Cunning triumphs over force, skill over bravery. The head of the army commander exercises more influence over the success of his campaign than the arms of his soldiers. Intelligence shows courage the way, bravery is saved until the execution of the task.’ These propositions, written in 1758, are part of a study of Charles XII who seemed to be an exception to the rule. He owed nothing to artfulness and everything to nature, as Frederick wrote during the Seven Years War. But was it not this very thing which plunged Sweden’s King into misfortune? Since Charles XII was more brave than skilful, more active than clever, more a slave to his passions than was good for him, according to Frederick one should only follow his example with caution. The example of the Swedish ruler should rather be an opportunity to impress upon young people ‘that bravery is nothing without 219wisdom and that a calculating head ultimately triumphs over daring boldness’. Thus Charles XII, whom Frederick secretly admired but who also represented a warning of the possibility of his own downfall, failed to pass the ultimate test of great military leadership. He serves to confirm the view that the conduct of war was a matter of intelligence and education, and could not be left to ‘courage’ alone.