The Holy Grail is a treasure that serves as an important motif in Arthurian literature. Different traditions describe it as a cup, dish or stone with miraculous powers that provide happiness, eternal youth or sustenance in infinite abundance, often in the custody of the Fisher King. The term 'holy grail' is often used to denote an elusive object or goal that is sought after for its great significance. The Holy Grail is a treasure that serves as an important motif in Arthurian literature. Different traditions describe it as a cup, dish or stone with miraculous powers that provide happiness, eternal youth or sustenance in infinite abundance, often in the custody of the Fisher King. The term 'holy grail' is often used to denote an elusive object or goal that is sought after for its great significance. A 'grail', wondrous but not explicitly holy, first appears in Perceval, le Conte du Graal, an unfinished romance written by Chrétien de Troyes around 1190. Here, Chrétien's story attracted many continuators, translators and interpreters in the later 12th and early 13th centuries, including Wolfram von Eschenbach, who perceived the Grail as a stone. In the late 12th century, Robert de Boron wrote in Joseph d'Arimathie that the Grail was Jesus's vessel from the Last Supper, which Joseph of Arimathea used to catch Christ's blood at the crucifixion. Thereafter, the Holy Grail became interwoven with the legend of the Holy Chalice, the Last Supper cup, a theme continued in works such as the Vulgate Cycle, the Post-Vulgate Cycle, and Le Morte d'Arthur. Grail literature divides into two classes. The first concerns King Arthur's knights visiting the Grail castle or questing after the object. The second concerns the Grail's history in the time of Joseph of Arimathea. The word graal, as it is earliest spelled, comes from Old French graal or greal, cognate with Old Provençal grazal and Old Catalan gresal, meaning 'a cup or bowl of earth, wood, or metal' (or other various types of vessels in different Occitan dialects). The most commonly accepted etymology derives it from Latin gradalis or gradale via an earlier form, cratalis, a derivative of crater or cratus, which was, in turn, borrowed from Greek krater (κρᾱτήρ, a large wine-mixing vessel). Alternative suggestions include a derivative of cratis, a name for a type of woven basket that came to refer to a dish, or a derivative of Latin gradus meaning ''by degree', 'by stages', applied to a dish brought to the table in different stages or services during a meal'. In the 15th century, English writer John Hardyng invented a fanciful new etymology for Old French san-graal (or san-gréal), meaning 'Holy Grail', by parsing it as sang real, meaning 'royal blood'. This etymology was used by some later medieval British writers such as Thomas Malory, and became prominent in the conspiracy theory developed in the book The Holy Blood and the Holy Grail, in which sang real refers to the Jesus bloodline.