This book takes a look at the lengthy chain of forts built by the French to guard the frontier in the American northeast, including Sorel, Chambly, St Jean, Carillon (Ticonderoga), Duquesne (Pittsburgh, PA), and Vincennes. These forts were of two types: the major stone forts, and other forts made of wood and earth, all of which varied widely in style from Vauban-type elements to cabins surrounded by a stockade. Some forts, such as Chambly, looked more like medieval castles in their earliest incarnations. René Chartrand examines the different types of forts built by the French, describing the strategic vision that led to their construction, their impact upon the British colonies and the Native American nations of the interior, and the French military technology that went into their construction.