The Black Company by Glen Cook

The Black Company is a seminal dark fantasy book series by Glen Cook, following a mercenary company through morally ambiguous wars, told from the perspective of its medic and historian, Croaker. Known for its gritty realism, military focus, and cynical tone, it's considered a foundational work of the grimdark subgenre, blending high fantasy with the perspective of a common soldier. The series is divided into several story arcs, including Chronicles of the Black Company, The Books of the South, and The Return of the Black Company.