This book looks at Irish Gothic and horror texts, in both English and Irish, from the beginning of the nineteenth century to the end of the twentieth, examining how this kind of fiction represented the cultural and political concerns of the day through the deployment of monsters, both as characters and as representative figures. Monsters disrupt both our definition of ‘history’ (as a record of past events arranged into a narrative structure) and our scientific, political, or ‘common sense’ understanding of what is possible or impossible; the monster exists outside any notion of a universal morality (or even moral relativism), and with its strange biology it complicates ideologies of gender and race. To be confronted by a monster is to witness the breakdown accepted models of reality, and plunges the subject into a nihilistic world where human action is meaningless. Since Irish history is often conceived of as a sequence of ‘ruptures’ (e.g. the Plantations, the 1641 Rebellion, the Great Famine, the Anglo-Irish War and the Troubles), monstrosity is an apt lens through which to scrutinise Irish culture. Each chapter of this book looks at a different category of monster in turn, and looks at the distinctive ways in which they rupture human history.