Two entries with the name Yder.
Edern, Edyrn, Hider, Hiderus, Hudos, Ide, Ider, Ides, Idres, Idrous, Idrus, Isder, Itiers, Ridek, Ydes, Ydet, Ydier, Ydras, Ydrys
A king and Knight of the Round Table who first appears in Culhwch and Olwen.
Evidence suggests a widespread popularity of this hero in the before the early thirteenth century, after which his character lost importance. The appearance of Yder on the Modena Archivolt (in the early twelfth century in Italy) testifies as to his early fame. In Welsh texts, we learn only that he was the son of Nudd (probably from Nodens, an Celtic divinity), that he had two brothers named Owain and Gwynn, and that he was the leader of Arthur’s Danish warriors. In Geoffrey of Monmouth, he fights, wins honor, and perishes in Arthur’s war against Rome. Geoffrey gives him a son named Her.
A passage – almost certainly an interpolation – in William of Malmesbury’s Historia Rerum Anglicarum has a young Yder fight three giants on the mountain called Ranae or Brent Knoll. Arthur had embarked with a troop to take care of the ravaging monsters, but Yder went on ahead of the company and encountered them alone. He managed to slay all three giants, but was seriously wounded in the process. Arthur assumed he was dead and made an endowment at Glastonbury for two dozen monks to pray for Yder’s soul.
We next meet Yder in Chrétien de Troyes’s Erec. During a hunt, Guinevere and Erec come across Yder and his dwarf. Yder’s dwarf insults Guinevere and Yder does nothing about it. Intent on avenging the insult, Erec follows Yder to the town of Laluth, where Yder is the annual victor in a Sparrowhawk Tournament. Erec enters the tournament, defeats Yder, and sends him to Arthur’s court. This story is also related in the Welsh Geraint with identical circumstances. In the Norse Erex Saga, his character is replaced by Malpirant.
In the late twelfth or early thirteenth century, a romance of Yder was written in French. In this anti-Arthurian tale, a young Yder sets off on a quest for his vanished father, Nut. During the quest, he visits Queen Guenloie of Carvain and falls in love with her, but is dismissed from her court until he has proven himself. He eventually joins Arthur’s court after saving the king from two knights, but is disillusioned with Arthur’s behavior and soon departs. He is knighted by a king named Ivenant, and he receives a squire named Luguain from another nobleman. His further adventures again bring him into contact with Arthur, who, along with Kay, tries to murder him. He eventually finds his father, saves Guinevere from a bear, and slays two giants, thus proving himself to Queen Guenloie. Yder and the queen are married at Arthur’s court, and Yder becomes a king himself. We must note that “Guenloie” is a variation of “Guinevere”, and that Yder is one of Guinevere’s rescuers on the Modena Archivolt. It has been suggested that in an early Breton story, Yder was Guinevere’s lover, occupying roughly the same role filled by Lancelot in French romance. There is an allusion to this romance in the Folie Tristan of Berne.
In the Vulgate Merlin and in Arthour and Merlin, “Yder of the Dolorous Mount” takes a different role (this Yder is perhaps a different character). Named as the king of Cornwall in the former and the king of Nantes in the latter, he is one of the kings to rebel against Arthur at the beginning of Arthur’s reign. After the battle of Bedegraine, in which Yder and his allies are defeated, Yder’s land is invaded, ravaged, and plundered by the Saxons. Several defeats against the Saxons lead Yder to swear fealty to Arthur. The Saxons are soon crushed at the battle of Clarence. As in Geoffrey, Yder goes on to serve Arthur in the Roman War and in the war against Galehaut of Sorelois.
We find Yder in a collection of other texts. In the First Continuation of Chrétien’s Perceval, he has a son named Yonet. In La Vengeance Raguidel, he helps Gawain avenge the death of Sir Raguidel against Sir Guengasoain. While Gawain duels Guengasoain, Yder fights and slays Guengasoain’s bear, which recalls his similar deed in Yder. Yder marries Guengasoain’s daughter, Trevilonete.
The Alliterative Morte Arthure and Malory, oddly, name him as the son of Yvain, perhaps confusing his relationship to Owain in Welsh texts. He is only an incidental character in Malory, with no hint as to his popularity three to four hundred years earlier. Tennyson returns him to his role as Geraint’s Sparrowhawk Tournament opponent, adding that he was Enide’s cousin and that he forced Enide’s father into poverty when he refused to let Yder wed Enide. Tennyson places his death at the battle of Camlann.
Chrétien names this king as among Arthur’s allies and advisors. We meet him again fighting in the Noauz tournament, where his shield is identified by a stag emerging from a gate.
Do not confuse him with Yder son of Nut, but c.f. Ider and King Idres.