The "Volto Santo", the great crucifix of Lucca, is situated in the Cathedral of St. Martin, placed inside a little shrine that was built by Matteo Civitali out of Carrara marble in 1484.

According to the ancient legend as told by Deacon Leobino, the "Volto Santo" or "Holy face" was sculptured by Nicodemus, who is mentioned in the Gospel as having witnessed the resurrection and ascension into heaven of Christ and could therefore reproduce the exact characteristics of Christ'’ face. The legend says that having completed all but the face, Nicodemus fell asleep. Upon awaking the face was finished. He had been helped by angels come from heaven. During the persecutions Nicodemus was an old man and decided to give the statue to Isacar for safekeeping. Isacar kept it hidden so that no-one could damage or steal it. From then on the Holy face was worshipped with a great deal of devotion until Bishop Gualfried discovered it, hidden away in a cave and decided to send it across the seas in a boat, lit up with dozens of candles to guide it along its way, in the hope of finding a land which would worship it as it justly deserved. The boat miraculously reached the port of Luni. Meanwhile, an angel appeared to the Bishop of Lucca, telling him to go and fetch a wooden crucifix whose face was the exact replica of Christ’s.

When entering the Port of Luni, the boat sailed directly towards the Bishop of Lucca who managed to secure it. However, the people of Luni were displeased and claimed the cross for themselves. The Bishop of Lucca therefore offered them an urn containing Christ’s blood as a compromise, which was accepted. The cross arrived in Lucca in 742 AD. And its fame spread quickly across the land.

Frescoes recounting the legend of the Holy Cross can be seen in the private chapels of Noble Lucchesi families e.g. the Buonvisi villa near Monte San Quirico. The image of the Holy Face can be seen inside the city walls on at least two of the main gates. Outside the walls some lovely images can be seen in Borgo Giannotti (1850) and Montignoso (1631).

The feast of the Exhaltation of the Cross is held on September 14. An impressive procession takes place along the streets of Lucca called "the Luminara di Santa Croce". It begins in the church of St. Frediano where the cross was originally situated and ends up in the church of St. Martino.