Cathedral of Notre-Dame de Paris

Notre-Dame's construction, begun in 1163 under Bishop Maurice de Sully and continuing for close to two centuries, made it one of the most ambitious Gothic buildings of its age, but its role as custodian of major Passion relics came slightly later and through a specific royal transaction rather than through the cathedral's own foundation. King Louis IX, later canonised as Saint Louis, purchased the Crown of Thorns from Baldwin II, the financially desperate Latin emperor of Constantinople, in 1238 to 1239, paying a vast sum to redeem it from Venetian creditors to whom Baldwin had pawned it.

Louis judged the relic too important for the cathedral alone and built the Sainte-Chapelle, a purpose-made royal reliquary chapel within the royal palace on the same island, specifically to house the Crown and the other Passion relics he acquired in the same years. The Crown of Thorns moved to Notre-Dame only later, after the Sainte-Chapelle lost its royal function following the French Revolution; the cathedral has held it since the nineteenth century as the closest surviving major ecclesiastical building to its original royal chapel, displaying it on Fridays in Lent and on Good Friday rather than continuously.

When fire broke out in Notre-Dame's roof structure on 15 April 2019, the cathedral's medieval timber spire and roof were destroyed within hours, but the Crown of Thorns and the cathedral's other treasury relics were not stored in the burning structure itself; a chaplain and Paris fire brigade personnel formed a chain to remove the reliquary from the cathedral's treasury as the fire spread, and the relic left the building safely rather than surviving flames in place. This distinguishes the Crown's survival from cases such as the Shroud of Turin's 1532 chapel fire, where the relic itself was inside the burning structure.

The relic's authenticity as the Crown worn by Jesus rests entirely on its documented ownership history from the Byzantine and Crusader courts of Constantinople backward, since no earlier material trace connects any surviving woven rush crown to first century Judaea; the thorns once mounted on it were dispersed as gifts to European rulers and churches over the centuries and no longer accompany the base relic Notre-Dame displays. The cathedral, following the Catholic Church's general practice with such objects, presents it as an object of devotion whose historical authenticity is a matter of faith and tradition rather than one it claims to have independently verified.