The opening years of the French and Indian War were disastrous for the British. Hindered by quarrelsome provincial councils, incompetent generals, and the redcoats' inability to adapt to wilderness warfare, Britain was losing the war. Learning that most of Britain's military resources were allocated to Louisbourg, the French launched a campaign along the weakened frontier. French Commander Louis-Joseph de Montcalm and his American Indian allies laid siege to Fort William Henry; Monro could not hold out and was forced to surrender. As part of the terms, the British regiment, colonial militia, and their camp followers would be allowed safe passage to nearby Fort Edward. The French watched in horror, however, as their Indian allies attacked the British column after it left the fort, an episode that sparked outrage and changed the tactics of the war.

Seen through the eyes of participants such as Louis Antoine de Bougainville, a scholarly young aide-de-camp, Jabez Fitch, an amiable Connecticut sergeant, and Kisensik, a proud Nipissing chief whose father once met Louis XIV in the marbled halls of Versailles, The Siege of Fort William Henry uses contemporary newspaper reports, official documents, private letters, and published memoirs to bring the narrative to life.