Lord Charles Cornwallis' failure to exercise the competencies expected of senior strategic leaders resulted in the loss of the American colonies to the British Empire. Why did Cornwallis surrender at Yorktown in October of 1781 when a large British relief force (under Sir Henry Clinton) was in route from New York? Is it possible that Cornwallis, regarded as the best British commander in America, simply did not comprehend the strategic importance of this battle in determining the outcome of the war and American independence? The purpose of this study is to examine Lord Charles Cornwallis as a "failed" practitioner of the strategic leadership competencies as they are defined in the U.S. Army War College's Strategic Leadership Primer. Using the framework of the competencies overlaid on Cornwallis' Revolutionary War career, this study will illustrate that the development of great strategic leaders can be a dangerous learning process fraught with costly errors in judgment, particularly while operating within the fog of war. The relevance of this examination is that it provides a vehicle from which developing senior leaders can gain insight into the strategic leadership competencies by studying the early strategic failures of a future British military/political "superstar'' who was thrust into a volatile, uncertain, complex and ambiguous environment in the American colonies.