In this dissertation, I explore the intersection between fraternity and governance within fifteenth-century English literature, arguing that the familial relationships in these texts go beyond the interpersonal and are used by the authors to think through questions of both self-governance and the governing of the polity. Drawing on methods used by historians of emotions, such as Barbara Rosenwein, I trace the usage of terms indicating brotherhood across a variety of genres (romances, plays, sermons, letters, and wills), and consider the depictions of brothers' behaviours, motivations, and speeches in these texts. This analysis reveals that governance and fraternity are linked in several unique but complementary manners in fifteenth-century England, and that authors utilize fraternal relationships to demonstrate a wide variety of good and bad governance of self and others. In each chapter, I trace the discourses of fraternity within a unique conceptual framework: Scriptural foundations, Classical foundations, the Rise of Arthur, the Fall of Arthur, and the Rise of the Gentry. The variety and prominence of discourses of fraternity within the genres and texts studied here demonstrate the power of brotherhood in the cultural imaginary of the period. The authors of these texts all grapple with the doubleedged sword of fraternity, exploring how characters navigate the complexities of brotherhood. The authors use fraternity as a tool to explore how interpersonal relationships can have a larger influence on the polity around them, proving that fraternity, much like authority, can be used and abused for personal gain, often to the detriment of others. This project has been made possibly through the love, support, guidance, and encouragement of all the wonderful people in my life. I cannot thank everyone individually who has made this journey not only possible but enjoyable, but please know that I appreciate you all. The past six years have been some of the best of my life, and I am forever grateful for those in my life who helped make that happen.To Dr. Siobhain Bly Calkin: Your guidance and wisdom have been invaluable to me over the last six years. Whether it be through copious feedback on my work or through our meetings which could last hours, your advice consistently improved my work and encouraged me to push my own limits and have allowed me to emerge a stronger scholar for it. It has been a pleasure and a privilege to be your student and I will be forever grateful for the investment you made in me and my work.