Such images functioned as powerful relics as well as icons, and their images were naturally seen as especially authoritative as to the true appearance of the subject. Like icons believed to be painted from the live subject, they therefore acted as important references for other images in the tradition. They therefore were copied on an enormous scale, and the belief that such images existed, and authenticated certain facial types, played an important role in the conservatism of the Byzantine tradition. Beside, and conflated with, the legend of the Image of Edessa, was the tale of the Veil of Veronica, whose very name signifies "true icon" or "true image", the fear of a "false image" remaining strong.
Surviving examples of this genre bear a marked resemblance to each other and have contributed to the bearded image of Jesus generally recongnisable up to the present day. The respect accorded to these traditions remains much stronger in the Eastern Orthodox Church; many Latin Catholic images, such as the Virgin of Guadalupe, have accrued such traditions, but with the exception of the Shroud of Turin and some of the others discussed below, these are not encouraged by the Holy Roman Catholic Church.
Such icons were seen as powerful arguments against iconoclasm. In a document apparently produced in the circle of the Patriach of Constantinople, which purports to be the record of a Church council of 836, a list of acheiropoieta and icons miraculously protected is given as evidence for divine approval of icons. The acheiropoieta listed are:
- The Image of Edessa, described as still at Edessa;
- The image of the Virgin at Lydda in Israel, which was said to have miraculously appeared imprinted on a column of a church built by the apostles Peter and John;
- Another image of the Virgin, three cubits high, at Lydda in Israel, which was said to have miraculously appeared in another church.
This list seems to have had a regional bias, as other than famous images are not mentioned, such as the Christ of Camuliana, later brought to the capital. Another example, which indisputably still exists, is a mosaic of the young Christ from the sixth century in the church of the Latomos monastery in Thessaloníki dedicated to Saint David. This was apparently covered by plaster during the Iconoclastic period, towards the end of which an earthquake caused the plaster to fall down, revealing the image (during the reign of Leo V, 813-20). However this was only a subsidiary miracle, according to the account we have. This says that the mosaic was being constructed secretly, during the 4th century persecution of Galerius, as an image of the Virgin, when it suddenly was transformed overnight into the present image of Christ.
According to Christian legend, the Image of Edessa, known to Orthodox Christians as the Mandylion, a Byzantine Greek word not applied in any other context, was a holy relic consisting of a square or rectangle of cloth upon which a miraculous image of the face of Jesus was imprinted — the first icon, which all others are based.
According to the legend, King Abgar of Edessa wrote to Jesus, asking him to come cure him of an illness. Abgar received an answering letter from Jesus, declining the invitation, but promising a future visit by one of his disciples. Along with the letter went a likeness of Jesus. This legend was first recorded in the early fourth century by Eusebius of Caesarea, who said that he had transcribed and translated the actual letter in the Syriac chancery documents of the king of Edessa. Instead, the apostle "Thaddaeus" is said to have come to Edessa, bearing the words of Jesus, by the virtues of which the king was miraculously healed.
Veronica's Veil, known in Italian as the Volto Santo or Holy Face (but not to be confused with the carved crucifix Volto Santo of Lucca) is a legendary religious relic. Some people believe that Veronica from Jerusalem encountered Jesus along the Via Dolorosa on the way to Calvary. When she paused to wipe the sweat (Latin suda) off his face with her veil, his image was imprinted on the cloth. The event is commemorated by one of the Stations of the Cross. According to legend, Veronica later traveled to Rome to present the cloth to the Roman Emperor Tiberius. Legend has it that it has miraculous properties, being able to quench thirst, restore sight, and sometimes even raise the dead.
After being for centuries the most revered and copied Catholic image of Christ, in recent times it has rather been overshadowed by the Shroud of Turin.
The Shroud of Turin (or Turin Shroud) is a linen cloth bearing the hidden image of a man who appears to have been physically traumatized in a manner consistent with crucifixion. The image is most clearly visible as a photographic negative, as was first observed in 1898 on the reverse photographic plate when amateur photographer Secondo Pia was unexpectedly allowed to photograph it. The shroud is kept in the royal chapel of the Cathedral of Saint John the Baptist in Turin, Italy. The Roman Catholic Church has approved this image in association with the devotion to the Holy Face of Jesus and some believe it is the cloth that covered Jesus at burial.
The Lateran Palace Image, also called the Uronica, is kept in what was once the pope’s private chapel, in a room now known as the Sancta Sanctorum ("Holy of Holies") at the top of the Scala Sancta ("Holy Stairs") in a surviving part of the old Lateran Palace in Rome. The legend is that this icon was begun by St Luke and finished by angels.
It is thought that the icon was over-painted in Rome between the 5th and 6th century. Today only slight traces under overpainting remain of the original image of an enthroned Christ with a crossed halo, in the classic pose of the Teacher holding the roll of the law in His left hand with His right raised in benediction. Many times restored, the face completely changed when Pope Alexander III (1159-1181) had the present one, painted on silk, placed over the original. Innocent III (1189-1216) covered the rest of the holy icon with embossed silver, but other later embellishments have by now completely disguised its surface. It has also been cleaned during the recent restoration. The doors protecting the icon, again in embossed silver, are of the 15th century. It has a baldachin in metal and gilded wood over it, replacing the one by Caradaossi (1452-1527), lost during the sack of Rome in 1527. The image itself was last inspected by the Jesuit art historian J. Wilpert in 1907.
As early as the reign of Pope Sergius I (687–701) there are records of the image being carried in annual procession at certain feasts, and Stephen II (752–757) carried the image on his shoulders in a procession to counter a threat from the Lombards. By the ninth century its elaborate procession had become a focus of the Feast of the Assumption. In the Middle Ages the Pope and the seven cardinal-bishops would celebrate masses in the small sanctuary where it was housed, and at times would kiss its feet. Although no longer a specific liturgical object, some Romans still venerate this icon, considering it a last hope in disasters and memorable events in the capital, a veneration which can be compared with that for the other ancient icon of the Madonna “Salus Populi Romani” in St. Mary Major, again in Rome. The former icon used to be taken across Rome annually in procession to "meet" the latter on the Feast of the Assumption.