The Shroud of Turin also known as the Holy Shroud is a 14-foot linen cloth bearing an image of a crucified man that has become a popular Catholic icon. For some, it is the authentic burial shroud of Jesus Christ.
First mentioned in 1354, the shroud was denounced in 1389 by the local bishop of Troyes as a fake. Currently the Catholic Church neither formally endorses nor rejects the shroud, and in 2013 the current Pope Francis referred to it as an "icon of a man scourged and crucified". The shroud has been kept in the royal chapel of the Cathedral of Turin, in northern Italy, since 1578.
In 1988, radiocarbon dating established that the shroud was from the Middle Ages, between the years 1260 and 1390. Some shroud researchers have challenged this carbon dating, arguing the results were skewed by the introduction of material from the Middle Ages to the portion of the shroud used for radiocarbon dating.
Diverse arguments have been made in scientific and popular publications claiming to prove that the cloth is the authentic burial shroud of Jesus, based on disciplines ranging from chemistry to biology and medical forensics to optical image analysis. However, all of the hypotheses put forward to challenge the radiocarbon dating have been scientifically refuted, including the medieval repair hypothesis, the bio-contamination hypothesis and the carbon monoxide hypothesis.
The image on the shroud is much clearer in black-and-white negative first observed in 1898—than in its natural sepia color. A variety of methods have been proposed for the formation of the image, but the actual method used has not yet been conclusively identified. The shroud continues to be both intensely studied and controversial.