Merciless captain of fortune, Giangiacomo de’ Medici was born into a family of the decadent Milanese nobility in 1498. While he was not linked by blood to the more famous Florentine lineage, his political and military fortune nevertheless partly depended upon it. After an unsuccessful attempt to found a state in the territories around Lake Como, he built his military reputation as a condottiere by taking advantage of the permanent conflict and political disorder in sixteenth-century Italy. He spent his last twenty years, until his death in 1555, as a general of Charles V, distinguishing himself in various European war scenarios.

Franco Minonzio reconstructs the biography of this man and his time in a dense and well-documented book. Already author of extensive research on the Milanese condottiere, Minonzio chooses to focus on the political and military career of Giangiacomo de’ Medici—also called Medeghino because of his short stature—when his dominion over the Lake Como region (1532–55) had come to an end. The Nietzsche quote in the title of this work, “how one becomes what one is,” epitomizes the sense of Minonzio's historical analysis. Through this perspective, the author decides not to dissociate the second phase of Giangiacomo's career from the first, but rather to present his younger years as the foundation of his later military fortune. A precise methodological approach guides the investigation: Minonzio's central concern is to restore a portrait of the Medici purified from the myth built up by popular anecdotes, the apologetic propaganda of the sixteenth and seventeenth centuries, and late Romantic historiography. To do so, he relies on a wide range of evidence, including unpublished and little-known sources (e.g., historical writings, memoirs, and letters), some of which are transcribed in the different chapters and in the rich appendix. As a result, a image of Giangiacomo de’ Medici takes shape through the constant intersection of testimonies.

The volume comprises nine chapters. In the first two chapters the author sets out his methodological choices and retraces his subject's youthful years. Giangiacomo appears to be particularly turbulent from a young age: accused of murder, he used his knowledge of the Lombard territory around Lake Como to take refuge and escape conviction. Here, he joined a band of bandits and later made the fortress of Musso his power base. Between 1523 and 1532, he tried to create a territorial state on the Lario but eventually had to give up in the face of hostility from Duke Francesco II Sforza. As compensation, he was awarded the title of marquis of Marignano. From the third chapter onward, we follow Giangiacomo's career as a general in the service of the Habsburg army in Flanders (1539–40); in Hungary (1542); on the Marne; in Mühlberg (1547); in Bohemia (1547–48); and finally in Italy, in the wars of Parma (1551–52) and Siena (1554).

Minonzio pays particular attention to this last conflict, in which—to use the author's words—the marquis would complete a “process of political and military individuation” (19). Hired by the Gran Duke of Florence Cosimo I, Giangiacomo violently dominated the revolt of the Sienese Republic, which received the support of French militia and the Florentine exiles of the anti-Medicean party. In Siena, he committed heinous crimes against civilians, as contemporary pro-Medicean and anti-Medicean testimonies attest. Confronted with the general's ruthlessness, the author explores the culture of warfare of the time, pondering about the extent of brutality in Giangiacomo's conduct. The answer leaves no doubt: judging by the contemporary reflections on buona guerra and mala guerra, his methods were indeed unorthodox. From Minonzio's perspective, the reasons for this cruelty, which have often been glossed over in the historiography, must be sought in Medeghino's life experiences. Coming from a family of fallen nobility, he had a contempt for commoners and poverty; having spent part of his life in a band of brigands, he had little track with ethical military codes; aspiring to princely status, he nourished a profound aversion to republican values.

Minonzio's monograph is not a biography in the traditional sense, nor does it aspire to be. Looking at a key figure in the complex geopolitics of the early sixteenth century, the author provides a rich reading of the sociopolitical context of Central and Northern Italy. His analysis allows us to deepen our understanding of Italian Wars from a different point of view, exploring the crisis of the Renaissance institutions through the experience of one of its seemingly minor actors. This book is therefore a valuable contribution for anyone interested in this troubled phase of early modern European history.