Lying in the Cathedral of Oviedo, Spain in relative obscurity compared to its more famous cousin, the Sudarium presents a better provenance and history than the Shroud and may be the sole surviving relic of the crucifixion that has made it to modern times.
Measuring 34" by 21", the Sudarium is a bloodstained cloth purported to have covered the head of Jesus of Nazareth after his burial. The cloth is mentioned to have been in the tomb in John 20:6-7 described as a cloth separate from the shroud. It isn't mentioned again until 570 A.D. when it was being kept by monks in a cave near Jerusalem. In 614, just before the Sasanian King of Persia Khusru II conquered Jerusalem, the cloth was taken to Alexandria, and within just a few years made its way to Spain through North Africa. Its been there ever since.
Unlike most relics, which tend to be medieval forgeries, the Sudarium is much different in both its clear provenance and history, and the fact that it really isn't all that impressive to look at. It has no miraculous images, its not a spear or a nail, or a crown of thorns. Its a blood stained cloth that covered the head of someone who died a very brutal death. To determine whether it's real or fake, Dr. Jose Villalain performed an investigation that showed that the victim died in an upright position, and the stains are comprised mostly of fluid from the lungs, along with blood. This illustrates death by asphyxiation while bleeding, consistent with crucifixion, which tends to suffocate the victim rather than cause death from blood loss. The stains are superimposed on top of one another, suggesting that some of the stains were at least partly dried when the body was moved again causing new fluid to deposit. The folds of the Sudarium suggest that the cloth was put in place while the body was in an upright position, perhaps still on the cross. There are smaller bloodstains present that may suggest a crown of thorns. Pollen samples taken from the cloth by Dr. Max Frei are consistent with Jerusalem, North Africa and Spain.
It has also been argued that there are clear correlations between the stains on the Sudarium and the Shroud of Turin, and the two seem to be made from very similar cloth. While the debate rages on about the authenticity of the Shroud, the Sudarium's clear history has protected it from the same level of controversy. Radiocarbon dating done by Baima Bollone showed the Sudarium to date from the 6th century, but Bollone stated that the dating is probably unreliable.
We know that the person who wore the Sudarium died a violent death consistent with crucifixion. We know it dates from at least the 6th century, probably before. And we know that the cloth was in Jerusalem. The one question that remains is who's head did it cover. In the world of relics, most are highly questionable. Some are outright ridiculous, such as The Most Holy Umbilical Cord. But this one simple piece of cloth may be as close as we will ever get to a true relic of the passion.