By Defeating My Enemies is a military biography of Charles XII of Sweden, the first written in English in over 50 years. It challenges several traditions created by historians of both the old and new schools of Carolean historiography and through a chronological review provides a balanced account of the king’s life. Ample space is dedicated to exploring the undervalued pre-war life of the king as his upbringing influenced key decisions on war and how he waged it. As the Great Northern War begins, Charles’s involvement on the battlefield and his deep connection with the Carolean army are studied to assess his growth as a commander. The king is followed into the crucible of the Polish-Lithuanian Commonwealth, the fateful march on Russia, exile in Ottoman territory, and the desperate rearguard actions culminating in a second invasion of Norway and his mysterious death at Fredriksten fortress. Had Charles not inherited the crown, he would be ranked among the great generals of the period