The book you are referring to is likely , written by Manuel Martínez Peinado (often abbreviated or misspelled as "Manuel Martin" in searches). It is a historical novel set in the early Roman Republic.

Beyond the battlefield, the "Memoirs of Medulino" delve into the social fractures of Rome. Camillus, a staunch patrician, must balance his loyalty to his class with the growing demands of the plebeians for political representation and economic relief. The novel explores how internal political instability was often as dangerous as any foreign army, showing how Camillus’s own exile—driven by political rivals—symbolizes the "city eternal" eating its own heroes. Themes of Duty and Exile

The novel’s primary tension stems from Rome’s precarious position in central Italy. Martínez Peinado vividly depicts the constant threat posed by neighboring tribes like the Volsci and Aequi, but the true shadow over Rome is the Etruscan city of Veii. By chronicling Camillus’s journey, the author highlights the transformation of Rome from a small settlement into a regional power. The legendary ten-year siege of Veii serves as a narrative anchor, illustrating the shift from seasonal tribal skirmishes to professionalized, long-term Roman warfare. Internal Conflict: The Patrician-Plebeian Struggle