Made in gold and enamel and decorated with precious stones, the Holy Thorn Reliquary depicts the salvation of mankind through the sacrifice of Christ. It was commissioned around 1400-10 by Jean, duc de Berry, a member of the French royal family, to house a single thorn from the relic of Christ's Crown of Thorns. Having left the duke's possession, it was recorded in Vienna from around 1544 until the 1860s, eventually being acquired by a member of the wealthy Rothschild family, with its true identity remaining undiscovered until the twentieth century. This book explores the meaning and history of this fascinating object, and tells the tale of its remarkable survival and eventual passage to the British Museum.