 King Louis IX of France bought what he believed to be the authentic Crown of Thorns in Constantinople in 1239, and individual thorns were distributed as gifts by subsequent French kings. John, Duke of Berry (1340 – 1416), brother of King Charles V of France, had this reliquary made to house a single thorn; it was probably made a few years before he commissioned his famous Très Riches Heures du Duc de Berry, and some years after he commissioned the Royal Gold Cup, also in the British Museum. Previously dated between 1401 and 1410, from evidence in John Cherry's book of 2010 the reliquary is now thought to have been made before 1397; based on the heraldic forms used, the museum now dates it to 1390 – 97. The Holy Thorn Reliquary was later thought to have been in the possession of Louis I, Duke of Orléans, but all recent writers prefer his brother, the Duke of Berry.
