PROTESTANT reformer John Calvin said that, if all the relics of the "True Cross" were genuine, there would be enough to fill a ship.
The veneration of relics has been going strong since the fourth century when St Helena, mother of Emperor Constantine of Rome, carried out excavations on the site of where Calvary was thought to be and discovered three crosses.
A sick man was brought to touch each of them in turn and, when he was cured after touching the third, this was decided to be the True Cross.
This cross was eventually divided up into hundreds of smaller relics -- some just splinters -- which were sent to churches and monasteries across Europe.
These were then venerated by the faithful, some of whom believed they had healing powers.
By the end of the Middle Ages, fakes were rife, with travelling merchants duping gullible customers.
There were so many forgeries that Dutch philosopher Erasmus is said to have remarked Christ must have been crucified on a "whole forest".
However, French architect Charles Rohault de Fleury set about disproving this and, after years of research, decided that, if all the pieces known of were put together, they would make up only a tiny fraction of the True Cross.
A relic of the True Cross was recently given to the people of Drogheda in Co Louth as a gift by the Bishop of Ghent in Belgium and is on display in St Peter's Church there.
The relic stolen from Holycross was presented to the abbey by King Donal Mor O'Brien in 1180.
It is unclear how he came to have it, however he was searching for a safe place to keep it and decided to entrust to the abbey's monks.
It became a source of devotion and pilgrimage at the abbey for almost 900 years.