The Sudarium of Oviedo throws new light on the last hours of Jesus of Nazareth. It provides a better understanding of the gospel John 20:5-7 and some characteristics of the Shroud of Turin that explain since when the use of the Sudarium is known. During the past few decades, those interested in the Shroud of Turin have also been eager to know what this book reveals about the Sudarium of Oviedo, because it reinforces the possibility that both cloths were used on the same Man. This book presents to English-speaking readers the research on the Sudarium of Oviedo, most of which has only been available in Spanish so far. It includes a thorough critical analysis and new unpublished studies. The bloodstained cloth is claimed to be a relic of Christ. This text discusses its trace through history, the many tests performed directly on it or on its samples, its devotional value, and its comparison with the Shroud of Turin.