Derek Mahon (1941-2020) is widely recognized as one of the most important Irish poets of his generation. This collection of new critical essays offers an important retrospective assessment of the nature of his poetic achievement. Bringing together many leading scholars of modern and contemporary Irish poetry, including a notable number of accomplished poet-critics, its contributors range widely across Mahon's body of work. Their essays offer fresh considerations of the biographical, geographical and literary contexts that shaped his poetic voice. This includes paying attention not only to more familiar influences but also to previously little considered interlocutors. The stylistic and formal achievement of his voice is re-evaluated in ways that range from attentive close readings to considerations of his controversial practice of self-revision, and his engagements with music and experiments in translation. The politics of a poet often misleadingly considered apolitical are also reframed to take in the engagements of his early work through to the ecocritical commitment of his later poetry. Indeed, a notable aspect of this book is the consideration it gives to all the phases of Mahon's career. As a whole, the collection opens up many new ways of reading and understanding Mahon's important body of work.