Сер Лаунфаль: Ұлыбритания және Франция әдебиеттерінен алынған ортағасырлық жыр.

Sir Launfal is a 1045 line Middle English romance or Breton lay written by Thomas Chestre dating from the late 14th century. which in turn was based on Marie de France's lai Lanval, written in a form of French understood in the courts of both England and France in the 12th century. Sir Launfal retains the basic story told by Marie and retold in Sir Landevale, augmented with material from an Old French lai Graelent and a lost romance that possibly featured a giant named Sir Valentyne. This is in line with Thomas Chestre's eclectic way of creating his poetry. In the tale, Sir Launfal is propelled from wealth and status – the steward at King Arthur's court – to being a pauper and a social outcast. He is not even invited to a feast in his home town of Caerleon when the king visits, although Arthur knows nothing of this. Out in the forest alone, he meets with two damsels who take him to their mistress, the daughter of the King of Faerie. She gives him untold wealth and a magic bag in which money can always be found, on the condition that he becomes her lover. She will visit him whenever he wants and nobody will see her or hear her. But he must tell nobody about her, or her love will vanish at that instant. The story of a powerful (fairy) woman who takes a lover on condition that he obey a particular prohibition is common in medieval poetry: the French lais of Desiré, Graelent, and Guingamor, and Chrétien de Troyes's romance Yvain, the Knight of the Lion, all share similar plot elements. The presence of a Land of Faerie, or an Otherworld, betrays the story's Celtic roots. A final court scene may be intended by Chestre as criticism of the contemporary legal and judicial framework in late 14th century England. and is based principally upon an early 14th century English romance Sir Landevale, itself an adaptation of Marie de France's Old French Breton lai, Lanval. It is widely accepted that Thomas Chestre was the author of two other verse romances in MS Cotton Caligula A. ii., Lybeaus Desconus and the Southern Octavian.

In this story, Arthur is king of England (also referred to as Bretayn) and holds court in Carlisle and Glastonbury, particularly during such summer feasts as Pentecost and Trinity Sunday. There is ambiguity, though. Kardevyle, where the opening scene of the story takes place, can be interpreted as Carlisle, in northern England, where King Arthur holds court in many Middle English romances, such as the Awntyrs off Arthure and The Wedding of Sir Gawain and Dame Ragnelle. But it can also be interpreted as Cardiff, in South Wales, which is King Arthur's residence in Sir Gawain and the Carle of Carlisle, and might sit more comfortably with the other locations in Sir Launfal, such as Caerleon and Glastonbury. Marie de France's poem Lanval, along with other Old French Arthurian works, has this city as "Kardoel", which, given the confusion, must have sounded, even to a late Medieval English ear, like a conflation of Carlisle and Cardiff. In Marie's poem, however, the intention seems clearly to be Carlisle, since King Arthur is fighting against Scots and Pictish incursions there. Guenevere (Gwennere, Gwenore) is stated by Thomas Chestre to be from "Irlond", possibly Ireland, the daughter of King Rion, who is an enemy of King Arthur in most other medieval Arthurian stories and usually hails from North Wales. Launfal's home base seems to be Caerleon, in South Wales. The realm of Fayrye is located on the island of Olyroun (probably Oléron, near Brittany). Being the realm of Fayrye, however, it might not be expected to have a specific location in the real world. Marie de France relates that Lanval was taken by his Faërie lover to Avalon, "a very beautiful island," Also mentioned are knights of Little Britain (Brittany), and the need to cross the salt sea to reach Lombardy.

Marie de France's lai was composed at a time when the story of King Arthur was not fully developed, and probably before the story of the love between Lancelot and Queen Guinevere had been added to it by Chrétien de Troyes in his Knight of the Cart. Thomas Chestre describes a 10 year period during which Launfal prospers at Arthur's bachelor court, followed by Arthur's marriage to Guinevere. In the 13th century French Arthurian romances, Merlin warns against this marriage; in Chestre's poem, he arranges it, betraying Chestre's willingness to adapt an established legend in his own way. Such adaptation is further evident in Guinevere's blinding. Marie de France describes no such mutilation of the Queen, and it sits uncomfortably with the climax of King Arthur's reign, well known from the 13th century Lancelot Grail Cycle, in which Lancelot and a seeing Guinevere play their part in King Arthur's final days.

Many passages of Chestre's poem follow Marie de France's Lanval line by line (probably via the earlier English romance). However, he adds or changes scenes and characters, sometimes working in material from other sources, and makes explicit and concrete many motivations and other aspects of the story which Marie leaves undiscussed—for example, the fairy purse and other gifts, such as the horse Blaunchard and the invisible servant Gyfre, who both depart when he breaks his promise not to boast. Some of these additional elements are derived from an Old French lai of Graelent, Arthur generally comes off much better in Sir Launfal than in Lanval, and Guenevere much worse; she is promoted to a major character, with more speeches and actions, and her comeuppance is the climax of the poem. Chestre also adds the Mayor of Caerleon, a character who is not present in Lanval and whose grudging disloyalty gives extra gloss to the generosity which Launfal shows when he obtains the fairy purse. Chestre adds two tournament scenes that are not present in Marie's lai, allowing him to show off his ability to fashion them and also changing the emphasis on his hero's character. He also introduces Sir Valentyne, possibly from a lost romance. In general, Lanval is a story about love, whereas Sir Launfal is much more an adventure story which includes a love element.

Elements of Sir Launfal that borrow from Marie de France's Lanval can be found in other Breton lais as well, particularly the land of "Fayerye". Marie de France's Yonec, for example, describes a woman following a trail of blood left by her lover; a man who was accustomed to arriving at the window of her room in the form of a hawk. She follows the trail of blood into the side of a hill and out into an Otherworld where all the buildings are made of solid silver, into a town where ships are moored. Marie's lai Guigemar, sees the wounded hero set sail in a mysterious boat with candelabra at its prow and with only a bed on deck, upon which he lies, the only living soul on board. He arrives safely at the mysterious castle of a lady who heals him of his wound, and becomes her lover. Sir Orfeo follows a company of ladies into the side of a cliff and through the rock until he emerges into an Otherworld, in a Middle English Breton lai, where he rescues his wife who had been abducted, from amongst those who have been beheaded and burnt and suffocated. Many ancient Irish tales involve a hero entering a hill of the Sidhe, or crossing a sea to a Land of Youth, or passing down through the waters of a lake into an Otherworld. A Middle English poem, the Isle of Ladies, describes an island where magic apples sustain a multitude of ladies, and only ladies, on an island that is made of glass; like one of the Otherworldly islands that features in the ancient Irish legend, The Voyage of Máel Dúin. "If the Middle English Breton Lay has connections with Celtic folktale, the connections can be easily perceived in Sir Launfal.

Folktale elements inherited from Marie de France's Lanval include the fairy lover, magical gifts, a beauty contest and an offended fay. and Sir Cleges.

Launfal's breaking of his word not to reveal his lover's name may have contemporary medieval significance, since one of the tenets of Courtly love was "the code of avantance, in which the male was to protect his lover’s reputation by not revealing her identity." Marie de France's depiction of King Arthur's court in Lanval, two hundred years earlier, may have been intended to parody the court of King Henry II of England, who saw himself as a new Arthur.