The Hero of Italy examines a salient episode in Italy's Thirty Years' War with Spain and France, whereby the young duke Odoardo Farnese of Parma embraced the French alliance, only to experience defeat and occupation after two tumultuous years (1635-1637). Gregory Hanlon stresses the narrative of events unfolding in northern Italy, examining the participation of the little state in these epic European events.

The first chapter describes the constitution of Cardinal Richelieu's anti-Habsburg alliance and Odoardo's eagerness to be part of it. A chapter on the Parman professional army, based on an extraordinary collection of company roster-books, sheds light on the identity of over 13,000 individuals, soldier by soldier, the origin and background of their officers, the conditions of their lodgings, and the good state of their equipment. Chapter three follows the first campaign of 1635 alongside French and Savoyard contingents at the failed siege of Valenza, and the logistical difficulties of organizing such large-scale operations. Another chapter examines the financial expedients the duchy adopted to fend off incursions on all its borders in 1636, and how militia contingents on both sides were drawn into the fighting. A final chapter relates the Spanish invasion and occupation which forced duke Odoardo to make a separate peace. The volume includes a detailed assessment of the impact of war on civilians based on parish registers for city and country. The application of the laws of war was largely nullified by widespread starvation, disease and routine sex-selective infanticide. These quantitative analyses, supported by maps and tables, are among the most detailed anywhere in Europe in the era of the Thirty Years' War.