"Military leaders bestride the centuries capturing the attention of contemporaries and posterity. Names such as Caesar, Genghis Khan and Napoleon resound down the centuries. They indeed helped mould the contemporary world with their campaigns, but more than individual drive and ability were involved.
In addition, it is necessary to see how the campaigns of leaders interacted with the circumstances in which they operated. This is crucial because military success is a matter not of battle waged against an opaque background, but, instead, of the ability to fulfil objectives. In short, a task-based account of military achievement is necessary. This is key whether the leadership considered is at the tactical, operational or strategic levels.
These three levels are worthy of consideration because they indicate the variety of types of military leadership, and because to be a military leader at the highest level it was necessary to first succeed at the tactical level. There are exceptions, which we will come to, but let us fist consider the general case..."