Duke Chaleins of Clarence was a Knight of the Round Table who appeared occasionally at the Royal tournaments. He arrived at King Galehaut's meet in Sorelais with a companion named Sir Elis la Noire and was hailed as a great champion, despite having turned up late. At the Candlemas Tournament following the death of Lady Elaine of Astolat, he brought a hundred knights.

His Duchy of Clarence was a medieval creation, based on the lordship of Clare in Suffolk.