In this video, Neil MacGregor discusses the Holy Thorn Reliquary at the British Museum, video embedded with permission of the British Museum

Holy Thorn Reliquary (made in Paris for Jean, Duc de Berry), c. 1390s, gold, enamel, ruby, pearl, sapphire, and rock crystal, 30 × 14.2 × 6.8 cm (British Museum, London)

This sumptuous reliquary holds a single thorn from the crown of thorns bought by King Louis IX in Constantinople in 1239. The price was 135,000 livres, an enormous sum that speaks to the importance placed on this relic, believed to have been used to mock Christ during his trials and crucifixion. The remainder of the crown of thorns is in the Cathedrale Notre Dame de Paris. Jean, Duke of Berry was the brother of Charles V, the king of France. The goldsmith has not been identified. It is interesting to note that a copy of this original had been secretly substituted and had remained undetected in the royal Viennese collection for decades.

A relic is an object, often a portion of a saint’s body or clothing, that is ascribed with spiritual power. During the medieval era, relics were enormously important economic engines that could draw pilgrims to a church that held them in search of the blessings they were thought to bestow. A reliquary is a decorated container for a relic.