One Corpse Too Many by Ellis Peters

Set in the tumultuous period of 12th-century England during the civil war between King Stephen and Empress Maud, the story follows Brother Cadfael, a former soldier turned monk, who is drawn into a murder investigation when an extra body is discovered among the executed rebels. As Cadfael uses his keen observational skills and knowledge of human nature to unravel the mystery, he navigates a world of political intrigue and personal vendettas, ultimately seeking justice and peace amidst the chaos of war.