When war broke out between Great Britain and the United States in 1812, Sir George Prevost, captain general and governor in chief of British North America, was responsible for defending a group of North American colonies that stretched as far as the distance from Paris to Moscow. He also commanded one of the largest British overseas forces during the Napoleonic Wars. Defender of Canada, the first book-length examination of Prevost’s career, offers a reinterpretation of the general’s military leadership in the War of 1812. Historian John R. Grodzinski shows that Prevost deserves far greater credit for the successful defense of Canada than he has heretofore received. Earlier accounts portrayed Prevost as overly cautious and attributed the preservation of Canada to other officers, but Grodzinski challenges these assumptions and restores the general to his rightful place as British North America’s key military figure during the War of 1812. Grodzinski shows that Prevost’s strategic insight enabled him to enact a practicable defense despite scarce resources and to ably integrate naval power into his defensive plans. Prevost’s range of responsibilities in British North America were daunting. They included overseeing joint endeavors with Indian allies, managing logistical matters, monitoring naval construction and personnel needs, supervising colonial governments, and commanding the defense of Canada. Tasked with protecting an extensive and complex territory, Prevost employed a mix of soldiers, sailors, locally raised forces, and indigenous people in taking advantage of the American military’s weaknesses to defeat most of its plans. Following his recall to Britain in 1815 after the defeat at the Battle of Plattsburgh, Prevost would have been court-martialed had he not died unexpectedly. In carefully examining the charges leveled against Prevost, Grodzinski shows the general to have preserved the integrity of Canada, allowing diplomats to ensure its continued existence.