It has been an old custom for authors to offer to their Princes the fruits of their studies in belles letters, from a persuasion that no work can be published with propriety but under the auspices of the Emperor, and that the knowledge of a Prince should be more general, and of the most important kind, as its influence is felt so keenly by all his subjects. We have many instances of the favorable reception which Augustus and his illustrious successors conferred on the works presented to them; and this encouragement of the Sovereign made the sciences flourish. The consideration of Your Majesty’s superior indulgence for attempts of this sort, induced me to follow this example, and makes me at the same time almost forget my own inability when compared with the ancient writers. One advantage, however, I derive from the nature of this work, as it requires no elegance of expression, or extraordinary share of genius, but only great care and fidelity in collecting and explaining, for public use, the instructions and observations of our old historians of military affairs, or those who wrote expressly concerning them.