The crown is being displayed for three days in honor of the 800th anniversary of the birthday and christening of King Louis IX of France, who acquired it in 1239.
This important Christian symbol was used during the Crucifixion of Jesus to cause him pain and to mock his claim as king.
During the French Revolution, the relic found a home for a while in the Bibliothèque Nationale, later the Concordat of 1801 restored it to the Church, and it was deposited in the Cathedral of Notre-Dame.
The artifact has not made many appearances, only showing a few times in hundreds of years. The "Crown of Thorns" appeared once in 1997, and in 1939 on the eve of World War II, to celebrate seven centuries since it came to France.