By now the whole world has seen the heart-breaking destruction of much of Notre Dame de Paris. Thanks be to God, a priest managed to get the Blessed Sacrament out of the cathedral before the roof collapsed, and he rescued the relic of the Crown of Thorns (shown here) as well. You can read a detailed article about it here.
There’s perennial confusion about the relic of the Crown of Thorns. If it was really made of thorns, then why does the Paris relic consist of thorn-less rushes? And if the Crown is in Paris, then why does Rome also claim to possess these thorns? The answer is complicated and less than clear, but that’s not surprising: the transfers of these relics to Rome and Paris occurred in the 4th and 13th centuries respectively, so extant written sources are few and far between.
When Saint Helen, the mother of Rome’s first Christian Emperor, found Our Lord’s Cross in Jerusalem in the 300’s, she brought a portion of it back to Rome–together with the nails, the title, and at least some thorns. Next to her own home she constructed a chapel to hold these precious relics, and Rome’s Basilica of Santa Croce in Gerusalemme stands on the very same spot today. The elaborate reliquaries that now house these treasures were constructed in more recent centuries; but the relics themselves have always been here. Continuity, in this case, is a sign of authenticity: in other words, if these relics aren’t authentic, then somehow the mistake was made by Saint Helen herself (which isn’t too likely, given her relative proximity in time to Christ’s crucifixion, which had occurred “just” three centuries before). The two scary-looking thorns that sit behind bullet-proof glass in the basilica today have been here in Rome for roughly 1700 years.
But we know that Helen left some relics behind in Jerusalem, chief among them a part of Christ’s Cross. Literary evidence is scanty; but it would appear that she chose to bring to Rome not the entire Crown of Thorns, but only a part of it. Her son, Emperor Constantine, immediately began distributing slivers of wood from the Cross to important friends and bishops of other cities, and it may very well be that he gave thorns away as well. The Italian city of Vicenza has long claimed to have one of the thorns (you can read more about that here).
We know that in the 1200’s, King Saint Louis IX of France led an army of Crusaders in one of the many battles to regain control of the Holy Land, and returned to Paris with the Crown of Thorns. The Catholic Encyclopedia has a wonderfully detailed description of these events, which you can read here. When approaching Paris with this priceless relic, the devout monarch got off his horse and carried it into the city himself, his feet and head bare. Louis IX had the Sainte-Chapelle constructed specifically to house the Crown of Thorns, although after the French Revolution it ended up in the treasury of Notre Dame for safekeeping, and it’s been there ever since.
The Crown in Paris is actually made of rushes, and there are no thorns visible. One possible reason for this is that the rushes may have been tied around Christ’s Head by the Roman soldiers, to keep the mass of thorns in place. The wounds seen on the Shroud of Turin corroborate this (when clients tour the Basilica of Santa Croce with us, we always tell them all about it!). Another theory is that the rushes are of a type found in the Middle East which has thorns–yes, rushes such as this evidently do grow there!–and all the thorns were broken off and given away over the centuries as relics to other churches. This could explain why Rome has two of the thorns: Saint Helen may simply have broken some off to bring back to Rome, leaving the rest of the Crown in Jerusalem.
In any event, there’s no particular historical reason to doubt the authenticity of either the Crown of Thorns in Paris, or the two thorns here in Rome. We have here two different relics which on the surface may seem to contradict each other … but the more research you do, the more likely it is that the thorns and rushes that you see did indeed play a role in the Passion of Our Lord Jesus Christ.