Napoleon's rise to power in the late eighteenth century occurred at a time when the structure of most European armies was based on the paradigm army of Frederick the Great. Napoleon, however, changed all of this and in a few short years transformed the French army into the most powerful force on the continent of Europe. During the period of 1805 to 1813, Napoleon's army had no equal with regard to operational effectiveness. Speed and positioning of forces were the two main characteristics that made the French army so successful. These same two characteristics were also inherent to French cavalry units. Thus, the central research question is: What influence did cavalry have upon Napoleon's operations? To facilitate this study, two campaigns were examined that illustrate cavalry's impact on Napoleon's operations. The first campaign was the Jena Campaign of 1806; the second was the Saxony Campaign of 1813. The Jena Campaign demonstrated that with the employment of sufficient and well- trained cavalry, Napoleon could render his victories decisive through the complete destruction of the enemy army. Conversely, the Saxony Campaign demonstrated that without the effective employment of sufficient and well-trained cavalry, Napoleon could not obtain the complete destruction of the enemy army and thus, his victories were hollow, or at best Pyrrhic. Therefore, based on the analysis of these two campaigns, this study has concluded that Napoleon's cavalry was a key element for Napoleon achieving complete destruction of the enemy army, thus rendering his victories decisive.