Guide published on occasion of the presentation of the Treasure of the Dolphin in a new exhibition space in the Museo del Prado from June, 2018. Philip V, the first Spanish Bourbon monarch and grandson of Louis XIV, inherited an exceptional group of vessels from his father Louis of France, the Grand Dauphin (1661-1711). Made of rock crystal and decorative stones traditionally known as “hardstones”, most are embellished with gold and silver mounts and with diamonds, rubies, emeralds, pearls and other gems. This collection is known as the Dauphin’s Treasure. The rarity of the materials used for creations of this type, their conceptual complexity and the technical skill involved in their making and decoration all explain why they were so highly esteemed, often above works of art now considered more important. This guide offers an introduction to the Dauphin’s Treasure, its origins, the materials used in its creation and the different workshops involved. It also discusses the Treasure’s eventful history and the valuable cases that protected the works. Since 2018 this unique collection has been on display in its entirety at the Museo del Prado.