Hoel or Howel (Welsh: Hywel) is a legendary king of Brittany and one of the oldest characters associated with Arthurian legend. He is the son of King Budic (or Boudicius) of Brittany, and serves as one of King Arthur's vassals and loyal allies. In Welsh literature, where he appears as Hywel fab Emyr Llydaw, his father is named Emyr Llydaw ("Emyr of Brittany"), and certain legends pertain he was the father of Saint Tudwal.
Hoel and the Arthurian legend
As Hywel fab Emyr Llydaw, Hoel is associated with Arthur's retinue in medieval Welsh texts like The Dream of Rhonabwy, Geraint and Enid, and Peredur son of Efrawg, and is an important figure in Geoffrey of Monmouth's work of pseudohistory, Historia Regum Britanniae, where his name appears in the Latinised form Hoel. Geoffrey confuses Hoel's relationship to Arthur over the course of his narrative; at first, it appears he is the son of Budic of Brittany and Aurelius Ambrosius and Uther Pendragon's sister, and therefore Arthur's first cousin. Later, however, Geoffrey claims Arthur's sister Anna married Budic, making Hoel Arthur's nephew. This confusion is picked up by Geoffrey's followers like Wace and Layamon; most later texts are content to call him Arthur's "cousin."
In Geoffrey, Hoel is Arthur's staunch ally, a Breton kinsman who comes to his aid in Britain to help quell the revolts that arise after the young king's coronation. He proves himself to be a capable general and a respected ruler. His niece is raped and killed by the Giant of Mont Saint-Michel, and Arthur sets off himself to slay the giant with the aid of his knights Kay and Bedivere. When Arthur returns to Britain to fight his traitorous nephew Mordred, he leaves Hoel in charge of Gaul.
When Hoel joins the Round Table he leaves his loyal nephew, Joseph, in charge of his kingdom.
Hoel and Tristan and Iseult
Hoel was later attached to the Tristan and Iseult legend by poets including Béroul and Thomas of Britain. In these stories, Hoel is duke of Brittany and the father of Tristan's unloved wife, Iseult of the White Hands. He takes Tristan in when the young knight has been banished from King Mark's kingdom, and Tristan later helps him in battle and becomes fast friends with his son Kahedin and his daughter Iseult. Tristan convinces himself to marry this second Iseult, mostly because she shares the name of his first love, Iseult of Ireland. In early versions of the story, Tristan remains in Hoel's land until he dies of poison (minutes before Iseult of Ireland, a great healer, arrives to cure him). The Prose Tristan has the hero returning to Britain and to his first love, never to see his wife again. This version was followed by the Post-Vulgate Cycle and Sir Thomas Malory's Le Morte d'Arthur...