The search for the Holy Grail is indeed a mystery for some Spanish Catholics since they claim that it was never lost.

According to the Spanish tradition, St. Peter took the Cup of the Last Supper from Jerusalem and sent it to Rome. In Rome this became the Chalice of the Popes, from the time of St. Peter to the time of Pope Sixtus II. In the year 258, during the Pontificate of Pope Sixtus II, the Roman emperor Valerianus signed an edict appropriating the possessions of all Christians. Sixtus II gave the papal treasures, including the Cup, to his Spanish deacon, later known as St. Lawrence. Before St. Lawrence was killed, he gave the Cup to a Spanish soldier who transferred it to Huesca (Spain).

In 553, Vicentius, bishop of Huesca, placed the Holy Chalice at the new church in this town, where it remained for 158 years. In 711, Muslims invaded Spain. For the next seven hundred plus years the Cup went from one hiding place to another until in 1424, Alfonso V , King of Valencia, Aragon, Majorca, Naples and Sicily, brought the Holy Grail, now known as the Santo Caliz, to the Royal Palace of Valencia. In 1437, Alfonso's brother, Don Juan, King of Navarre placed the Grail in the Cathedral of Valencia, where it resides today.

The Cup has only been taken from the Cathedral twice: during the War of Independence against Napoleon (1809-1813) it was moved to Alicante, Ibiza and Palma of Majorca; and during the Spanish Civil War (1936-1939) it was hidden at private homes in Carlet and Valencia.

In 1982, His Holiness Pope John Paul II came to Valencia, where he celebrated Mass with the Santo Caliz. After an interruption of one thousand seven hundred and twenty four years, a Pope was able to celebrate the Mass with the Holy Grail.