Origins

According to some versions of the legend, Ys was built below sea level by Gradlon (Gralon in Breton), King of Cornouaille (Kerne in Breton), upon the request of his daughter Dahut (also called Ahes), who loved the sea.

In others, Ys was founded more than 2000 years before Gradlon's reign in a then-dry location off the current coast of the Bay of Douarnenez, but the Breton coast had slowly given way to the sea so that Ys was under it at each high tide when Gradlon's reign began.

To protect Ys from inundation, a dike was built with a gate that was opened for ships during low tide. The one key that opened the gate was held by the king.

Fall

Ys was the most beautiful and impressive city in Europe, but quickly became a city of sin under the influence of Dahut. She organized orgies and had the habit of killing her lovers when morning broke. Saint Winwaloe decried the corruption of Ys and warned of God's wrath and punishment, but was ignored by Dahut and the populace.

One day, a knight dressed in red came to Ys. Dahut asked him to come with her, and one night, he agreed. A storm broke out in the middle of the night and the waves could be heard smashing against the gate and the bronze walls. Dahut said to the knight: "Let the storm rage. The gates of the city are strong, and it is King Gradlon, my father, who owns the only key, attached to his neck." The knight replied: "Your father the king sleeps. You can now easily take his key." Dahut stole the key from her father and gave it to the knight, who was none other than the devil. The devil, or, in another version of the story, a wine-besotted Dahut herself, then opened the gate.

Because the gate was open during storm and at high tide, a wave as high as a mountain collapsed on Ys. King Gradlon and his daughter climbed on Morvarc'h, his magical horse. Saint Winwaloe approached them and told Gradlon: "Push back the demon sitting behind you!" Gradlon initially refused, but he finally gave in and pushed his daughter into the sea. The sea swallowed Dahut, who became a mermaid or morgen.

Gradlon took refuge in Quimper, which became his new capital. An equestrian statue of Gradlon still stands between the spires of the Cathedral of Saint Corentin in Quimper. Folklore asserts that the bells of the churches of Ys can still be heard in the sea calm. A legend says that when Paris will be swallowed, the city of Ys will rise up from under the waves: Pa vo beuzet Paris, Ec'h adsavo Ker Is (Par-Is meaning "similar to Ys" in Breton).

This history is also sometimes viewed as the victory of Christianity over druidism, as Gradlon was converted by Saint Winwaloe. Dahut and most inhabitants of Ys were worshippers of Celtic gods. However, another Breton folktale asserts that Gradlon met, spoke with and consoled the last Druid in Brittany, and oversaw his pagan burial, before building a chapel in his sacred grove.

While legends and literature about Gradlon are much older, such as the Lai de Graelent by Marie de France probably written in the late 12th century, the story of Ys appears to have developed between the end of the fifteenth century and the seventeenth century. An early mention of Ys appears in Pierre Le Baud's Cronicques et ystoires des Bretons in which Gradlon is the king of the city, but Dahut is not mentioned. Bernard d'Argentre's La histoire de Bretagne and mystery plays on the life of St. Winwaloe, in the sixteenth century, also provide early references to the city. The version of the story of Ys which appears in Albert Le Grand's Vie des Saincts de la Bretagne Armorique published in the seventeenth century already contains all the basic elements of the later story and has been said to be the first.

The legend of Ys was confined to the folk of Brittany until 1839, when T. Hersart de la Villemarqué published a collection of popular songs collected from oral tradition, the Barzaz Breizh. The collection achieved a wide distribution and brought Breton folk culture into European awareness. In the second edition, the poem 'Livaden Geris' ('The Submersion of Ker-Is') appeared. The same basic story elements are present, but in this version the holy man is instead St. Corentin. It appears that elements of the text of this version were adapted from the medieval Welsh poem 'Seithennin' about the legend of Cantre'r Gwaelod, a very similar Welsh legend about a land that disappeared beneath the ocean as a result of human error. In this version, Dahut steals the key at the incitement of a lover. Also, here the element of Dahut as a mermaid or morgen has appeared as the last verses of the song refer to a fisherman seeing a mermaid combing her hair and singing a sad song.

Emile Souvestre's Le Foyer Breton also played a great part in making the legend widely known, and many 19th century English tellings of the story are closely derived from the Foyer Breton's tale "Keris". In Souvestre's telling, the character of the Devil disguised as a man with a red beard has appeared.

Several famous artistic adaptations of the Ys legend appeared in the late 19th and early 20th century. E. V. Luminais' painting Flight of King Gradlon, depicting Gradlon's escape from Ys, scored a success at the Salon of 1884.

Le roi d'Ys, an opera by the French composer Édouard Lalo which premiered in 1888, transforms the story significantly, replacing the figure of Dahut with Margared, whose motive for opening the gates (with the aid of her own betrothed Karnac) is her jealousy at Rozenn's marriage to Mylio (characters who are also inventions of Lalo).

Also inspired by the story of Ys is Claude Debussy's La cathédrale engloutie, found in his first book of Preludes (published 1910). This is a prelude intended to evoke the atmosphere of the legend by its sound.

The legend of Ys has been used repeatedly in fantasy fiction, prominently by Robert W. Chambers in "The Demoiselle d'Ys", one of the stories in The King in Yellow, Chambers' best-known work. Poul Anderson and his wife Karen Anderson dealt with the legend in their The King of Ys tetralogy. Ys and other sunken/lost lands figure in Jack Vance's Lyonesse Trilogy. The sunken City of Ys is also mentioned in "Sword of Destiny", a book in "The Witcher" Saga written by Andrzej Sapkowski, and the manga Berserk. Terry Pratchett used the Legend of Ys as the basis for his Discworld novel Jingo.

A. S. Byatt's novel Possession: A Romance, which won the Booker Prize in 1990, makes frequent reference to Breton myth and legend, including the story of Ys.

Italian progressive rock band Il Balletto di Bronzo loosely based their 37 minute opus on the story of Ys, naming both the piece and the 1972 album on which it appears after the city.

Harpist/singer-songwriter Joanna Newsom released an album in 2006 called Ys.

The Japanese game studio Falcom have a series of games called Ys, with the first game released in 1987.

• Iram of the Pillars
• Hyperborea
• Thule
• Atlantis
• El Dorado
• Shamballa
• Rocabarraigh
• Lyonesse

• Guyot, Charles. The Legend of the City of Ys, Amherst, Mass.: University of Massachusetts Press, 1979.

• MacKillop, James. Myths and Legends of the Celts, London ; New York : Penguin Global, 2005, pp. 299–302. ISBN 978-0-14-101794-5.