My thesis investigates the cultural role of arms and armour in Cinquecento Florence, roughly spanning the reigns of Duke Cosimo I de’ Medici and his two sons Francesco I and Ferdinando I, 1537-1609. My study primarily draws on records from the Otto di Guardia e Balia, the magistracy responsible for handling judicial and criminal affairs in Medicean Florence. I also rely on documents from the grand ducal Medici del Principato collection of letters. Contemporary legislation, account books, inventories, and material objects additionally feature in my analysis. The introduction of my PhD illustrates the period’s affinity for warfare. I then review the literature that discusses Renaissance masculinity, violence, dress, and arms and armour, before introducing the four principle research areas discussed in my thesis. The first chapter “Everyday Armour: Civilians and Arms in Sixteenth-Century Florence” investigates the day-to-day prevalence of weapons and violence in the early modern city and its dominion. It focuses on the types of arms outlawed, the fiscal and corporal penalties commonly doled out to perpetrators, and the procedures for obtaining arms’ licences legally from the state. I also examine supplications requesting pardons and reductions in fines and sentences submitted to the court. “The Making, Adornment, and Maintenance of Armour” is my dissertation’s second chapter, which explores the materiality of arms and armour. This study investigates the extreme dearth of armourers active in Florence in this period, as well as reviews the processes of armour manufacturing and the technological advances in methods of adornment. The systems in place for obtaining armour at the Medici court are also discussed. In the third chapter, “The Modern Man: Firearms in Sixteenth-Century Florence,” I explore the effects of firearms, most notably the wheellock pistol, in Grand Ducal Tuscany. I review the practices, customs, and risks of using these new-fangled weapons, as well as discuss a handful of extant weapons from museum collections. Legislative procedures surrounding guns are also explored, as well as the workarounds that some inhabitants used to circumvent contemporary prohibitions. Arms and armour and their relation to contemporary men’s fashion is discussed in my fourth chapter, “Dressed to Kill: Male Fashion in Renaissance Italy.” This research explores the connection between arms, armour, and dress, particularly for the elite man in sixteenth-century Florence. Focusing on the account books of Niccolò di Luigi Capponi, this study examines the basic components of contemporary men’s fashion, the city’s sumptuary laws, and the role offensive weapons and defensive garments played in relation to men’s fashion. I lastly examine how wearing certain arms and armour on the body affected male behaviour and concepts of identity. My dissertation concludes by briefly revisiting the findings from the four chapters discussed above. Under this new lens, I review the tension that existed around arms, civility, and stately control. Finally, I close the thesis by examining how this period was reimagined by armour collectors in the late-nineteenth and early-twentieth centuries. With these men in mind, I demonstrate how Renaissance arms and armour became emblems of another kind of masculinity exhibited centuries later.