Ο Νονός by Mario Puzo

An influential Sicilian-American crime family navigates loyalty, power, and betrayal as its aging patriarch seeks to protect his empire and legacy; when his youngest son—originally determined to lead an honest life—is pulled into the family's violent business after an attack, he gradually embraces ruthless tactics and political maneuvering, revealing how ambition, honor, and corruption reshape both individuals and the society around them.