This thesis investigates the connection between militarism and manliness in the eighteenth century. By bringing a range of historical sources - including pamphlets, newspapers, and satirical prints - together with canonical literary and philosophical texts by Joseph Addison, David Hume, Adam Smith, Lawrence Sterne, Horace Walpole, and Henry Mackenzie, this study suggests that 'old' notions of a necessary connection between the male body and military service clashed with 'new' ideas of modern manliness in this period. However, this thesis does not construct a linear narrative of change; rather, it uncovers a debate in which public opinion became a crucial factor. The introduction indentifies the roots ofthe eighteenth-century military masculinity debate in the late seventeenth-century standing army controversy, and the body of this thesis traces the continuation of the debate in the printed literature surrounding five major naval courts martial: the trials of Admirals Mathews and Lestock, 1746, the trial of Admiral Byng, 1757, and the trials of Admirals Keppel and Palliser, 1779. These trials provided foci for the military masculinity debate and allowed a range of voices to contribute, not least the Admirals themselves. However, by pairing each case study with a contextualizing chapter, this thesis also aims to show that the military masculinity debate can be mapped alongside key cultural concerns in this period: politeness, the gothic, and sensibility.