The Shroud is a linen sheet about 4.4 by 1.1 metres bearing a faint, straw-coloured double image of a man, front and back, marked with wounds consistent with scourging, crucifixion and a lance thrust to the side. Its documented history begins in the 1350s at Lirey in France; it passed to the House of Savoy in 1453 and to Turin in 1578. In 1988 three laboratories at Oxford, Zurich and Arizona independently radiocarbon-dated small samples and reported, with high confidence, a date range of about 1260 to 1390, published in Nature in 1989.
Critics have argued the tested corner was a medieval repair or contaminated, and studies of the image chemistry, pollen and weave continue to be published on both sides; none has overturned the radiocarbon result in the mainstream scientific literature. The Catholic Church has never defined the Shroud as authentic. Popes have called it an icon and a mirror of the Gospel and have venerated it while leaving the question of origin to research, a stance the Archdiocese of Turin restates at each ostension.