Among the very few papyri devoted to the work of the Attic orator Lysias, one of the most interesting is certainly P. Oxy. XXXI 2537. Dated palaeographically to the late 2nd-early 3rd century CE, it contains the summaries of 22 Lysianic speeches, 18 of which were formerly unknown or known just by the title and brief quotations in lexicographers. And yet, despite the undeniable richness of this collection, the papyrus has generally received little attention from modern scholarship, and no complete survey of its many aspects of significance has been yet produced. This work aims to fill this gap: along with a new transcription and critical edition based on autopsy of the papyrus, this book provides a translation and the first exhaustive commentary of the text. Through careful textual and juridical analysis, the author examines both the relationship between summaries and speeches, with a discussion of the significant legal features of each procedure, and the overall importance of this papyrus for the history of the corpus of Lysias. The book will thus be of interest for papyrologists, legal historians, students of Attic oratory, and researchers in the field of the history of the material culture of Graeco-Roman Egypt alike.