Theodor Mommsen's monumental work 'Römische Geschichte' spans across all 6 volumes, offering a comprehensive account of Roman history. Mommsen's writing style is characterized by its meticulous attention to detail and thorough research, presenting a scholarly yet accessible narrative of Rome's political, social, and cultural development. As a prominent figure in the field of ancient history, Mommsen's work is highly regarded for its insightful analysis and groundbreaking interpretations of historical events. 'Römische Geschichte' is a seminal work that has shaped the study of Roman history for generations to come.