Osborne’s story draws on the rich tradition of Arthurian legends. Although scholars lack definitive proof that King Arthur was a historical person, some speculate that he was a 6th-century Welsh warrior who fought against Saxon invaders. King Arthur and his court appeared in Celtic folklore prior to the 11th century, and the legend’s popularity spread throughout Europe thanks to Geoffrey of Monmouth’s Historia regum Britanniae, or History of the Kings of Britain, which was composed between 1135 and 1139. Geoffrey’s work added his own innovations to the centuries-old tales that have since become quintessential pieces of Arthurian lore, including Merlin the magician, Queen Guinevere, and Arthur’s enmity with Mordred, which all feature in Osborne’s story.

Another key writer who expanded the Arthurian mythos is the late-12th century French poet Chrétien de Troyes. Chrétien’s verses portrayed King Arthur as “the ruler of a realm of marvels in five romances of adventure” and introduced the quest for the Holy Grail, which remains a frequent subject of Arthurian tales (“Arthurian Legend.” Britannica, 7 Mar. 2024). Osborne alludes to this famous legend by including Sir Percival and Sir Galahad, who undertake the quest for the Grail in different versions of the story, and by having Sir Galahad give Jack and Annie a cup.