El Libro del Cauallero Zifar, edited by Charles Philip Wagner, is a critical edition of one of the earliest known Spanish chivalric novels, believed to be written around 1300. Wagner's meticulous editing process involved cross-referencing photostat versions and original manuscripts to present a reliable text. He explores the text's literary relationships and sources, including its connection to Pseudo-Seneca and Oriental geographical influences, and highlights the textual variations and medieval scribal practices that have shaped it. Part I focuses on presenting the reconstructed text, with a promise of further critical apparatus and scholarly commentary to follow in Part II. This work is not only a valuable resource for understanding medieval Spanish literature, but also a testament to Wagner’s dedication to preserving and analyzing this significant literary artifact.